@ohos.rpc (RPC)

The RPC module implements communication between processes, including inter-process communication (IPC) on a single device and remote procedure call (RPC) between processes on difference devices. IPC is implemented based on the Binder driver, and RPC is based on the DSoftBus driver.

NOTE

• The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.

• This module supports return of error codes since API version 9.

Modules to Import

import rpc from '@ohos.rpc';

ErrorCode⁹⁺

The APIs of this module return exceptions since API version 9. The following table lists the error codes.

System capability: SystemCapability.Communication.IPC.Core

Name	Value	Description
CHECK_PARAM_ERROR	401	Parameter check failed.
OS_MMAP_ERROR	1900001	Failed to call mmap.
OS_IOCTL_ERROR	1900002	Failed to call ioctl with the shared memory file descriptor.
WRITE_TO_ASHMEM_ERROR	1900003	Failed to write data to the shared memory.
READ_FROM_ASHMEM_ERROR	1900004	Failed to read data from the shared memory.
ONLY_PROXY_OBJECT_PERMITTED_ERROR	1900005	This operation is allowed only on the proxy object.
ONLY_REMOTE_OBJECT_PERMITTED_ERROR	1900006	This operation is allowed only on the remote object.
COMMUNICATION_ERROR	1900007	Failed to communicate with the remote object over IPC.
PROXY_OR_REMOTE_OBJECT_INVALID_ERROR	1900008	Invalid proxy or remote object.
WRITE_DATA_TO_MESSAGE_SEQUENCE_ERROR	1900009	Failed to write data to MessageSequence.
READ_DATA_FROM_MESSAGE_SEQUENCE_ERROR	1900010	Failed to read data from MessageSequence.
PARCEL_MEMORY_ALLOC_ERROR	1900011	Failed to allocate memory during serialization.
CALL_JS_METHOD_ERROR	1900012	Failed to invoke the JS callback.
OS_DUP_ERROR	1900013	Failed to call dup.

MessageSequence⁹⁺

Provides APIs for reading and writing data in specific format. During RPC or IPC, the sender can use the write() method provided by MessageSequence to write data in specific format to a MessageSequence object. The receiver can use the read() method provided by MessageSequence to read data in specific format from a MessageSequence object. The data formats include basic data types and arrays, IPC objects, interface tokens, and custom sequenceable objects.

create

static create(): MessageSequence

Creates a MessageSequence object. This API is a static method.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
MessageSequence	MessageSequence object created.

Example

let data = rpc.MessageSequence.create();
console.log("RpcClient: data is " + data);

reclaim

reclaim(): void

Reclaims the MessageSequence object that is no longer used.

System capability: SystemCapability.Communication.IPC.Core

Example

let reply = rpc.MessageSequence.create();
reply.reclaim();

writeRemoteObject

writeRemoteObject(object: IRemoteObject): void

Serializes a remote object and writes it to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
object	IRemoteObject	Yes	Remote object to serialize and write to the MessageSequence object.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900008	proxy or remote object is invalid
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
}
let data = rpc.MessageSequence.create();
let testRemoteObject = new TestRemoteObject("testObject");
try {
  data.writeRemoteObject(testRemoteObject);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("Rpc write remote object fail, errorCode " + e.code);
  console.info("Rpc write remote object fail, errorMessage " + e.message);
}

readRemoteObject

readRemoteObject(): IRemoteObject

Reads the remote object from MessageSequence. You can use this API to deserialize the MessageSequence object to generate an IRemoteObject. The remote object is read in the order in which it is written to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
IRemoteObject	Remote object obtained.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900008	proxy or remote object is invalid
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
}
let data = rpc.MessageSequence.create();
let testRemoteObject = new TestRemoteObject("testObject");
try {
  data.writeRemoteObject(testRemoteObject);
  let proxy = data.readRemoteObject();
  console.log("RpcClient: readRemoteObject is " + proxy);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("Rpc write remote object fail, errorCode " + e.code);
  console.info("Rpc write remote object fail, errorMessage " + e.message);
}

writeInterfaceToken

writeInterfaceToken(token: string): void

Writes an interface token to this MessageSequence object. The remote object can use this interface token to verify the communication.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
token	string	Yes	Interface token to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeInterfaceToken("aaa");
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write interface fail, errorCode " + e.code);
  console.info("rpc write interface fail, errorMessage " + e.message);
}

readInterfaceToken

readInterfaceToken(): string

Reads the interface token from this MessageSequence object. The interface token is read in the sequence in which it is written to the MessageSequence object. The local object can use it to verify the communication.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	Interface token obtained.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

class Stub extends rpc.RemoteObject {
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    try {
      let interfaceToken = data.readInterfaceToken();
      console.log("RpcServer: interfaceToken is " + interfaceToken);
    } catch(error) {
      let e: BusinessError = error as BusinessError;
      console.info("RpcServer: read interfaceToken failed, errorCode " + e.code);
      console.info("RpcServer: read interfaceToken failed, errorMessage " + e.message);
    }
    return true;
  }
}

getSize

getSize(): number

Obtains the data size of this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Size of the MessageSequence instance obtained, in bytes.

Example

let data = rpc.MessageSequence.create();
let size = data.getSize();
console.log("RpcClient: size is " + size);

getCapacity

getCapacity(): number

Obtains the capacity of this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	MessageSequence capacity obtained, in bytes.

Example

let data = rpc.MessageSequence.create();
let result = data.getCapacity();
console.log("RpcClient: capacity is " + result);

setSize

setSize(size: number): void

Sets the size of the data contained in this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
size	number	Yes	Data size to set, in bytes.

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.setSize(16);
  console.log("RpcClient: setSize is " + data.getSize());
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc set size of MessageSequence fail, errorCode " + e.code);
  console.info("rpc set size of MessageSequence fail, errorMessage " + e.message);
}

setCapacity

setCapacity(size: number): void

Sets the storage capacity of this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
size	number	Yes	Storage capacity of the MessageSequence object to set, in bytes.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900011	parcel memory alloc failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.setCapacity(100);
  console.log("RpcClient: setCapacity is " + data.getCapacity());
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc memory alloc fail, errorCode " + e.code);
  console.info("rpc memory alloc fail, errorMessage " + e.message);
}

getWritableBytes

getWritableBytes(): number

Obtains the writable capacity (in bytes) of this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Writable capacity of the MessageSequence instance, in bytes.

Example

class Stub extends rpc.RemoteObject {
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    let getWritableBytes = data.getWritableBytes();
    console.log("RpcServer: getWritableBytes is " + getWritableBytes);
    return true;
  }
}

getReadableBytes

getReadableBytes(): number

Obtains the readable capacity of this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Readable capacity of the MessageSequence instance, in bytes.

Example

class Stub extends rpc.RemoteObject {
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    let result = data.getReadableBytes();
    console.log("RpcServer: getReadableBytes is " + result);
    return true;
  }
}

getReadPosition

getReadPosition(): number

Obtains the read position of this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Read position obtained.

Example

let data = rpc.MessageSequence.create();
let readPos = data.getReadPosition();
console.log("RpcClient: readPos is " + readPos);

getWritePosition

getWritePosition(): number

Obtains the write position of this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Write position obtained.

Example

let data = rpc.MessageSequence.create();
data.writeInt(10);
let bwPos = data.getWritePosition();
console.log("RpcClient: bwPos is " + bwPos);

rewindRead

rewindRead(pos: number): void

Moves the read pointer to the specified position.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
pos	number	Yes	Position from which data is to read.

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
data.writeInt(12);
data.writeString("sequence");
let number = data.readInt();
console.log("RpcClient: number is " + number);
try {
  data.rewindRead(0);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc rewind read data fail, errorCode " + e.code);
  console.info("rpc rewind read data fail, errorMessage " + e.message);
}
let number2 = data.readInt();
console.log("RpcClient: rewindRead is " + number2);

rewindWrite

rewindWrite(pos: number): void

Moves the write pointer to the specified position.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
pos	number	Yes	Position from which data is to write.

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
data.writeInt(4);
try {
  data.rewindWrite(0);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc rewind read data fail, errorCode " + e.code);
  console.info("rpc rewind read data fail, errorMessage " + e.message);
}
data.writeInt(5);
let number = data.readInt();
console.log("RpcClient: rewindWrite is: " + number);

writeByte

writeByte(val: number): void

Writes a byte value to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Byte value to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeByte(2);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write byte fail, errorCode " + e.code);
  console.info("rpc write byte fail, errorMessage" + e.message);
}

readByte

readByte(): number

Reads the byte value from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Byte value read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeByte(2);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write byte fail, errorCode " + e.code);
  console.info("rpc write byte fail, errorMessage" + e.message);
}
try {
  let ret = data.readByte();
  console.log("RpcClient: readByte is: " + ret);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write byte fail, errorCode " + e.code);
  console.info("rpc write byte fail, errorMessage" + e.message);
}

writeShort

writeShort(val: number): void

Writes a short integer to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Short integer to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeShort(8);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write short fail, errorCode " + e.code);
  console.info("rpc write short fail, errorMessage" + e.message);
}

readShort

readShort(): number

Reads the short integer from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Short integer read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeShort(8);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write short fail, errorCode " + e.code);
  console.info("rpc write short fail, errorMessage" + e.message);
}
try {
  let ret = data.readShort();
  console.log("RpcClient: readByte is: " + ret);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read short fail, errorCode " + e.code);
  console.info("rpc read short fail, errorMessage" + e.message);
}

writeInt

writeInt(val: number): void

Writes an integer to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Integer to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeInt(10);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write int fail, errorCode " + e.code);
  console.info("rpc write int fail, errorMessage" + e.message);
}

readInt

readInt(): number

Reads the integer from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Integer read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeInt(10);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write int fail, errorCode " + e.code);
  console.info("rpc write int fail, errorMessage" + e.message);
}
try {
  let ret = data.readInt();
  console.log("RpcClient: readInt is " + ret);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read int fail, errorCode " + e.code);
  console.info("rpc read int fail, errorMessage" + e.message);
}

writeLong

writeLong(val: number): void

Writes a long integer to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Long integer to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeLong(10000);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write long fail, errorCode " + e.code);
  console.info("rpc write long fail, errorMessage" + e.message);
}

readLong

readLong(): number

Reads the long integer from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Long integer read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeLong(10000);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write long fail, errorCode " + e.code);
  console.info("rpc write long fail, errorMessage" + e.message);
}
try {
  let ret = data.readLong();
  console.log("RpcClient: readLong is " + ret);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read long fail, errorCode " + e.code);
  console.info("rpc read long fail, errorMessage" + e.message);
}

writeFloat

writeFloat(val: number): void

Writes a floating-point number to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Floating-point number to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeFloat(1.2);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write float fail, errorCode " + e.code);
  console.info("rpc write float fail, errorMessage" + e.message);
}

readFloat

readFloat(): number

Reads the floating-pointer number from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Floating-point number read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeFloat(1.2);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write float fail, errorCode " + e.code);
  console.info("rpc write float fail, errorMessage" + e.message);
}
try {
  let ret = data.readFloat();
  console.log("RpcClient: readFloat is " + ret);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read float fail, errorCode " + e.code);
  console.info("rpc read float fail, errorMessage" + e.message);
}

writeDouble

writeDouble(val: number): void

Writes a double-precision floating-point number to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Double-precision floating-point number to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeDouble(10.2);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read float fail, errorCode " + e.code);
  console.info("rpc read float fail, errorMessage" + e.message);
}

readDouble

readDouble(): number

Reads the double-precision floating-point number from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Double-precision floating-point number read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeDouble(10.2);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write double fail, errorCode " + e.code);
  console.info("rpc write double fail, errorMessage" + e.message);
}
try {
  let ret = data.readDouble();
  console.log("RpcClient: readDouble is " + ret);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read double fail, errorCode " + e.code);
  console.info("rpc read double fail, errorMessage" + e.message);
}

writeBoolean

writeBoolean(val: boolean): void

Writes a Boolean value to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	boolean	Yes	Boolean value to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeBoolean(false);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write boolean fail, errorCode " + e.code);
  console.info("rpc write boolean fail, errorMessage" + e.message);
}

readBoolean

readBoolean(): boolean

Reads the Boolean value from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
boolean	Boolean value read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeBoolean(false);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write boolean fail, errorCode " + e.code);
  console.info("rpc write boolean fail, errorMessage" + e.message);
}
try {
  let ret = data.readBoolean();
  console.log("RpcClient: readBoolean is " + ret);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read boolean fail, errorCode " + e.code);
  console.info("rpc read boolean fail, errorMessage" + e.message);
}

writeChar

writeChar(val: number): void

Writes a character to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Single character to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeChar(97);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write char fail, errorCode " + e.code);
  console.info("rpc write char fail, errorMessage" + e.message);
}

readChar

readChar(): number

Reads the character from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Character read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeChar(97);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write char fail, errorCode " + e.code);
  console.info("rpc write char fail, errorMessage" + e.message);
}
try {
  let ret = data.readChar();
  console.log("RpcClient: readChar is " + ret);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read char fail, errorCode " + e.code);
  console.info("rpc read char fail, errorMessage" + e.message);
}

writeString

writeString(val: string): void

Writes a string to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	string	Yes	String to write. The length of the string must be less than 40960 bytes.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeString('abc');
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write string fail, errorCode " + e.code);
  console.info("rpc write string fail, errorMessage" + e.message);
}

readString

readString(): string

Reads the string from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	String read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeString('abc');
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write string fail, errorCode " + e.code);
  console.info("rpc write string fail, errorMessage" + e.message);
}
try {
  let ret = data.readString();
  console.log("RpcClient: readString is " + ret);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read string fail, errorCode " + e.code);
  console.info("rpc read string fail, errorMessage" + e.message);
}

writeParcelable

writeParcelable(val: Parcelable): void

Writes a Parcelable object to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	Parcelable	Yes	Parcelable object to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

class MyParcelable implements rpc.Parcelable {
  num: number = 0;
  str: string = '';
  constructor( num: number, str: string) {
    this.num = num;
    this.str = str;
  }
  marshalling(messageSequence: rpc.MessageSequence): boolean {
    messageSequence.writeInt(this.num);
    messageSequence.writeString(this.str);
    return true;
  }
  unmarshalling(messageSequence: rpc.MessageSequence): boolean {
    this.num = messageSequence.readInt();
    this.str = messageSequence.readString();
    return true;
  }
}
let parcelable = new MyParcelable(1, "aaa");
let data = rpc.MessageSequence.create();
try {
  data.writeParcelable(parcelable);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write parcelable fail, errorCode " + e.code);
  console.info("rpc write parcelable fail, errorMessage" + e.message);
}

readParcelable

readParcelable(dataIn: Parcelable): void

Reads a Parcelable object from this MessageSequence object to the specified object (dataIn).

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	Parcelable	Yes	Parcelable object to read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed
1900012	call js callback function failed

Example

import { BusinessError } from '@ohos.base';

class MyParcelable implements rpc.Parcelable {
  num: number = 0;
  str: string = '';
  constructor(num: number, str: string) {
    this.num = num;
    this.str = str;
  }
  marshalling(messageSequence: rpc.MessageSequence): boolean {
    messageSequence.writeInt(this.num);
    messageSequence.writeString(this.str);
    return true;
  }
  unmarshalling(messageSequence: rpc.MessageSequence): boolean {
    this.num = messageSequence.readInt();
    this.str = messageSequence.readString();
    return true;
  }
}
let parcelable = new MyParcelable(1, "aaa");
let data = rpc.MessageSequence.create();
data.writeParcelable(parcelable);
let ret = new MyParcelable(0, "");
try {
  data.readParcelable(ret);
}catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read parcelable fail, errorCode " + e.code);
  console.info("rpc read parcelable fail, errorMessage" + e.message);
}

writeByteArray

writeByteArray(byteArray: number[]): void

Writes a byte array to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
byteArray	number[]	Yes	Byte array to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
let ByteArrayVar = [1, 2, 3, 4, 5];
try {
  data.writeByteArray(ByteArrayVar);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write byteArray fail, errorCode " + e.code);
  console.info("rpc write byteArray fail, errorMessage" + e.message);
}

readByteArray

readByteArray(dataIn: number[]): void

Reads a byte array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Byte array to read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
let ByteArrayVar = [1, 2, 3, 4, 5];
try {
  data.writeByteArray(ByteArrayVar);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write byteArray fail, errorCode " + e.code);
  console.info("rpc write byteArray fail, errorMessage" + e.message);
}
try {
  let array: Array<number> = new Array(5);
  data.readByteArray(array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write byteArray fail, errorCode " + e.code);
  console.info("rpc write byteArray fail, errorMessage" + e.message);
}

readByteArray

readByteArray(): number[]

Reads the byte array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	Byte array read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
let byteArrayVar = [1, 2, 3, 4, 5];
try {
  data.writeByteArray(byteArrayVar);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write byteArray fail, errorCode " + e.code);
  console.info("rpc write byteArray fail, errorMessage" + e.message);
}
try {
  let array = data.readByteArray();
  console.log("RpcClient: readByteArray is " + array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read byteArray fail, errorCode " + e.code);
  console.info("rpc read byteArray fail, errorMessage" + e.message);
}

writeShortArray

writeShortArray(shortArray: number[]): void

Writes a short array to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
shortArray	number[]	Yes	Short array to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeShortArray([11, 12, 13]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read byteArray fail, errorCode " + e.code);
  console.info("rpc read byteArray fail, errorMessage" + e.message);
}

readShortArray

readShortArray(dataIn: number[]): void

Reads a short array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Short array to read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeShortArray([11, 12, 13]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write shortArray fail, errorCode " + e.code);
  console.info("rpc write shortArray fail, errorMessage" + e.message);
}
try {
  let array: Array<number> = new Array(3);
  data.readShortArray(array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read shortArray fail, errorCode " + e.code);
  console.info("rpc read shortArray fail, errorMessage" + e.message);
}

readShortArray

readShortArray(): number[]

Reads the short array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	Short array read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeShortArray([11, 12, 13]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write shortArray fail, errorCode " + e.code);
  console.info("rpc write shortArray fail, errorMessage" + e.message);
}
try {
  let array = data.readShortArray();
  console.log("RpcClient: readShortArray is " + array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read shortArray fail, errorCode " + e.code);
  console.info("rpc read shortArray fail, errorMessage" + e.message);
}

writeIntArray

writeIntArray(intArray: number[]): void

Writes an integer array to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
intArray	number[]	Yes	Integer array to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeIntArray([100, 111, 112]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write intArray fail, errorCode " + e.code);
  console.info("rpc write intArray fail, errorMessage" + e.message);
}

readIntArray

readIntArray(dataIn: number[]): void

Reads an integer array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Integer array to read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeIntArray([100, 111, 112]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write intArray fail, errorCode " + e.code);
  console.info("rpc write intArray fail, errorMessage" + e.message);
}
let array: Array<number> = new Array(3);
try {
  data.readIntArray(array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read intArray fail, errorCode " + e.code);
  console.info("rpc read intArray fail, errorMessage" + e.message);
}

readIntArray

readIntArray(): number[]

Reads the integer array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	Integer array read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeIntArray([100, 111, 112]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write intArray fail, errorCode " + e.code);
  console.info("rpc write intArray fail, errorMessage" + e.message);
}
try {
  let array = data.readIntArray();
  console.log("RpcClient: readIntArray is " + array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read intArray fail, errorCode " + e.code);
  console.info("rpc read intArray fail, errorMessage" + e.message);
}

writeLongArray

writeLongArray(longArray: number[]): void

Writes a long array to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
longArray	number[]	Yes	Long array to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeLongArray([1111, 1112, 1113]);
}catch(error){
  let e: BusinessError = error as BusinessError;
  console.info("rpc write longArray fail, errorCode " + e.code);
  console.info("rpc write longArray fail, errorMessage" + e.message);
}

readLongArray

readLongArray(dataIn: number[]): void

Reads a long array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Long array to read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeLongArray([1111, 1112, 1113]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write longArray fail, errorCode " + e.code);
  console.info("rpc write longArray fail, errorMessage" + e.message);
}
let array: Array<number> = new Array(3);
try {
  data.readLongArray(array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read longArray fail, errorCode " + e.code);
  console.info("rpc read longArray fail, errorMessage" + e.message);
}

readLongArray

readLongArray(): number[]

Reads the long array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	Long array read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeLongArray([1111, 1112, 1113]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write longArray fail, errorCode " + e.code);
  console.info("rpc write longArray fail, errorMessage" + e.message);
}
try {
  let array = data.readLongArray();
  console.log("RpcClient: readLongArray is " + array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read longArray fail, errorCode " + e.code);
  console.info("rpc read longArray fail, errorMessage" + e.message);
}

writeFloatArray

writeFloatArray(floatArray: number[]): void

Writes a floating-point array to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
floatArray	number[]	Yes	Floating-point array to write. The system processes Float data as that of the Double type. Therefore, the total number of bytes occupied by a FloatArray must be calculated as the Double type.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeFloatArray([1.2, 1.3, 1.4]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write floatArray fail, errorCode " + e.code);
  console.info("rpc write floatArray fail, errorMessage" + e.message);
}

readFloatArray

readFloatArray(dataIn: number[]): void

Reads a floating-point array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Floating-point array to read. The system processes Float data as that of the Double type. Therefore, the total number of bytes occupied by a FloatArray must be calculated as the Double type.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeFloatArray([1.2, 1.3, 1.4]);
}catch(error){
  let e: BusinessError = error as BusinessError;
  console.info("rpc write floatArray fail, errorCode " + e.code);
  console.info("rpc write floatArray fail, errorMessage" + e.message);
}
let array: Array<number> = new Array(3);
try {
  data.readFloatArray(array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read floatArray fail, errorCode " + e.code);
  console.info("rpc read floatArray fail, errorMessage" + e.message);
}

readFloatArray

readFloatArray(): number[]

Reads the floating-point array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	Floating-point array read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeFloatArray([1.2, 1.3, 1.4]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write floatArray fail, errorCode " + e.code);
  console.info("rpc write floatArray fail, errorMessage" + e.message);
}
try {
  let array = data.readFloatArray();
  console.log("RpcClient: readFloatArray is " + array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read floatArray fail, errorCode " + e.code);
  console.info("rpc read floatArray fail, errorMessage" + e.message);
}

writeDoubleArray

writeDoubleArray(doubleArray: number[]): void

Writes a double-precision floating-point array to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
doubleArray	number[]	Yes	Double-precision floating-point array to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeDoubleArray([11.1, 12.2, 13.3]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write doubleArray fail, errorCode " + e.code);
  console.info("rpc write doubleArray fail, errorMessage" + e.message);
}

readDoubleArray

readDoubleArray(dataIn: number[]): void

Reads a double-precision floating-point array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Double-precision floating-point array to read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeDoubleArray([11.1, 12.2, 13.3]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write doubleArray fail, errorCode " + e.code);
  console.info("rpc write doubleArray fail, errorMessage" + e.message);
}
let array: Array<number> = new Array(3);
try {
  data.readDoubleArray(array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read doubleArray fail, errorCode " + e.code);
  console.info("rpc read doubleArray fail, errorMessage" + e.message);
}

readDoubleArray

readDoubleArray(): number[]

Reads the double-precision floating-point array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	Double-precision floating-point array read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeDoubleArray([11.1, 12.2, 13.3]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write doubleArray fail, errorCode " + e.code);
  console.info("rpc write doubleArray fail, errorMessage" + e.message);
}
try {
  let array = data.readDoubleArray();
  console.log("RpcClient: readDoubleArray is " + array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read doubleArray fail, errorCode " + e.code);
  console.info("rpc read doubleArray fail, errorMessage" + e.message);
}

writeBooleanArray

writeBooleanArray(booleanArray: boolean[]): void

Writes a Boolean array to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
booleanArray	boolean[]	Yes	Boolean array to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeBooleanArray([false, true, false]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write booleanArray fail, errorCode " + e.code);
  console.info("rpc write booleanArray fail, errorMessage" + e.message);
}

readBooleanArray

readBooleanArray(dataIn: boolean[]): void

Reads a Boolean array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	boolean[]	Yes	Boolean array to read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeBooleanArray([false, true, false]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write booleanArray fail, errorCode " + e.code);
  console.info("rpc write booleanArray fail, errorMessage" + e.message);
}
let array: Array<boolean> = new Array(3);
try {
  data.readBooleanArray(array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read booleanArray fail, errorCode " + e.code);
  console.info("rpc read booleanArray fail, errorMessage" + e.message);
}

readBooleanArray

readBooleanArray(): boolean[]

Reads the Boolean array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
boolean[]	Boolean array read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeBooleanArray([false, true, false]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write booleanArray fail, errorCode " + e.code);
  console.info("rpc write booleanArray fail, errorMessage" + e.message);
}
try {
  let array = data.readBooleanArray();
  console.log("RpcClient: readBooleanArray is " + array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read booleanArray fail, errorCode " + e.code);
  console.info("rpc read booleanArray fail, errorMessage" + e.message);
}

writeCharArray

writeCharArray(charArray: number[]): void

Writes a character array to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
charArray	number[]	Yes	Character array to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeCharArray([97, 98, 88]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write charArray fail, errorCode " + e.code);
  console.info("rpc write charArray fail, errorMessage" + e.message);
}

readCharArray

readCharArray(dataIn: number[]): void

Reads a character array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Character array to read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeCharArray([97, 98, 88]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write charArray fail, errorCode " + e.code);
  console.info("rpc write charArray fail, errorMessage" + e.message);
}
let array: Array<number> = new Array(3);
try {
  data.readCharArray(array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read charArray fail, errorCode " + e.code);
  console.info("rpc read charArray fail, errorMessage" + e.message);
}

readCharArray

readCharArray(): number[]

Reads the character array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	Character array read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeCharArray([97, 98, 88]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write charArray fail, errorCode " + e.code);
  console.info("rpc write charArray fail, errorMessage" + e.message);
}
try {
  let array = data.readCharArray();
  console.log("RpcClient: readCharArray is " + array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read charArray fail, errorCode " + e.code);
  console.info("rpc read charArray fail, errorMessage" + e.message);
}

writeStringArray

writeStringArray(stringArray: string[]): void

Writes a string array to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
stringArray	string[]	Yes	String array to write. The length of a single element in the array must be less than 40960 bytes.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeStringArray(["abc", "def"]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write stringArray fail, errorCode " + e.code);
  console.info("rpc write stringArray fail, errorMessage" + e.message);
}

readStringArray

readStringArray(dataIn: string[]): void

Reads a string array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	string[]	Yes	String array to read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeStringArray(["abc", "def"]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write stringArray fail, errorCode " + e.code);
  console.info("rpc write stringArray fail, errorMessage" + e.message);
}
let array: Array<string> = new Array(2);
try {
  data.readStringArray(array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read stringArray fail, errorCode " + e.code);
  console.info("rpc read stringArray fail, errorMessage" + e.message);
}

readStringArray

readStringArray(): string[]

Reads the string array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string[]	String array read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let data = rpc.MessageSequence.create();
try {
  data.writeStringArray(["abc", "def"]);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write stringArray fail, errorCode " + e.code);
  console.info("rpc write stringArray fail, errorMessage" + e.message);
}
try {
  let array = data.readStringArray();
  console.log("RpcClient: readStringArray is " + array);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read stringArray fail, errorCode " + e.code);
  console.info("rpc read stringArray fail, errorMessage" + e.message);
}

writeNoException

writeNoException(): void

Writes information to this MessageSequence object indicating that no exception occurred.

System capability: SystemCapability.Communication.IPC.Core

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    if (code === 1) {
      console.log("RpcServer: onRemoteMessageRequest called");
      try {
        reply.writeNoException();
      } catch(error) {
        let e: BusinessError = error as BusinessError;
        console.info("rpc write no exception fail, errorCode " + e.code);
        console.info("rpc write no exception fail, errorMessage" + e.message);
      }
      return true;
    } else {
      console.log("RpcServer: unknown code: " + code);
      return false;
    }
  }
}

readException

readException(): void

Reads the exception information from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, sendMessageRequest() of the proxy object is called to send a message.

import { BusinessError } from '@ohos.base';

let option = new rpc.MessageOption();
let data = rpc.MessageSequence.create();
let reply = rpc.MessageSequence.create();
data.writeInt(1);
data.writeString("hello");
proxy.sendMessageRequest(1, data, reply, option)
  .then((result: rpc.RequestResult) => {
    if (result.errCode === 0) {
      console.log("sendMessageRequest got result");
      try {
        result.reply.readException();
      } catch(error) {
        let e: BusinessError = error as BusinessError;
        console.info("rpc read exception fail, errorCode " + e.code);
        console.info("rpc read no exception fail, errorMessage" + e.message);
      }
      let msg = result.reply.readString();
      console.log("RPCTest: reply msg: " + msg);
    } else {
      console.log("RPCTest: sendMessageRequest failed, errCode: " + result.errCode);
    }
  }).catch((e: Error) => {
    console.log("RPCTest: sendMessageRequest got exception: " + e.message);
  }).finally (() => {
    console.log("RPCTest: sendMessageRequest ends, reclaim parcel");
    data.reclaim();
    reply.reclaim();
  });

writeParcelableArray

writeParcelableArray(parcelableArray: Parcelable[]): void

Writes a Parcelable array to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
parcelableArray	Parcelable[]	Yes	Parcelable array to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

class MyParcelable implements rpc.Parcelable {
  num: number = 0;
  str: string = '';
  constructor(num: number, str: string) {
    this.num = num;
    this.str = str;
  }
  marshalling(messageSequence: rpc.MessageSequence): boolean {
    messageSequence.writeInt(this.num);
    messageSequence.writeString(this.str);
    return true;
  }
  unmarshalling(messageSequence: rpc.MessageSequence): boolean {
    this.num = messageSequence.readInt();
    this.str = messageSequence.readString();
    return true;
  }
}
let parcelable = new MyParcelable(1, "aaa");
let parcelable2 = new MyParcelable(2, "bbb");
let parcelable3 = new MyParcelable(3, "ccc");
let a = [parcelable, parcelable2, parcelable3];
let data = rpc.MessageSequence.create();
try {
  data.writeParcelableArray(a);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write parcelable array fail, errorCode " + e.code);
  console.info("rpc write parcelable array fail, errorMessage" + e.message);
}

readParcelableArray

readParcelableArray(parcelableArray: Parcelable[]): void

Reads a Parcelable array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
parcelableArray	Parcelable[]	Yes	Parcelable array to read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed
1900012	call js callback function failed

Example

import { BusinessError } from '@ohos.base';

class MyParcelable implements rpc.Parcelable {
  num: number = 0;
  str: string = '';
  constructor(num: number, str: string) {
    this.num = num;
    this.str = str;
  }
  marshalling(messageSequence: rpc.MessageSequence): boolean {
    messageSequence.writeInt(this.num);
    messageSequence.writeString(this.str);
    return true;
  }
  unmarshalling(messageSequence: rpc.MessageSequence): boolean {
    this.num = messageSequence.readInt();
    this.str = messageSequence.readString();
    return true;
  }
}
let parcelable = new MyParcelable(1, "aaa");
let parcelable2 = new MyParcelable(2, "bbb");
let parcelable3 = new MyParcelable(3, "ccc");
let a = [parcelable, parcelable2, parcelable3];
let data = rpc.MessageSequence.create();
let result = data.writeParcelableArray(a);
console.log("RpcClient: writeParcelableArray is " + result);
let b = [new MyParcelable(0, ""), new MyParcelable(0, ""), new MyParcelable(0, "")];
try {
  data.readParcelableArray(b);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read parcelable array fail, errorCode " + e.code);
  console.info("rpc read parcelable array fail, errorMessage" + e.message);
}

writeRemoteObjectArray

writeRemoteObjectArray(objectArray: IRemoteObject[]): void

Writes an array of IRemoteObject objects to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
objectArray	IRemoteObject[]	Yes	Array of IRemoteObject objects to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
    this.modifyLocalInterface(this, descriptor);
  }

  asObject(): rpc.IRemoteObject {
    return this;
  }
}
let a = [new TestRemoteObject("testObject1"), new TestRemoteObject("testObject2"), new TestRemoteObject("testObject3")];
let data = rpc.MessageSequence.create();
try {
  let result = data.writeRemoteObjectArray(a);
  console.log("RpcClient: writeRemoteObjectArray is " + result);
} catch(error) {
   let e: BusinessError = error as BusinessError;
   console.info("rpc write remote object array fail, errorCode " + e.code);
   console.info("rpc write remote object array fail, errorMessage" + e.message);
}

readRemoteObjectArray

readRemoteObjectArray(objects: IRemoteObject[]): void

Reads an array of IRemoteObject objects from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
objects	IRemoteObject[]	Yes	IRemoteObject array to read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
    this.modifyLocalInterface(this, descriptor);
  }

  asObject(): rpc.IRemoteObject {
    return this;
  }
}
let a = [new TestRemoteObject("testObject1"), new TestRemoteObject("testObject2"), new TestRemoteObject("testObject3")];
let data = rpc.MessageSequence.create();
data.writeRemoteObjectArray(a);
let b: Array<rpc.IRemoteObject> = new Array(3);
try {
  data.readRemoteObjectArray(b);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read remote object array fail, errorCode " + e.code);
  console.info("rpc read remote object array fail, errorMessage" + e.message);
}

readRemoteObjectArray

readRemoteObjectArray(): IRemoteObject[]

Reads the IRemoteObject object array from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
IRemoteObject[]	IRemoteObject object array read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
    this.modifyLocalInterface(this, descriptor);
  }

  asObject(): rpc.IRemoteObject {
    return this;
  }
}
let a = [new TestRemoteObject("testObject1"), new TestRemoteObject("testObject2"), new TestRemoteObject("testObject3")];
let data = rpc.MessageSequence.create();
data.writeRemoteObjectArray(a);
try {
  let b = data.readRemoteObjectArray();
  console.log("RpcClient: readRemoteObjectArray is " + b);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read remote object array fail, errorCode " + e.code);
  console.info("rpc read remote object array fail, errorMessage" + e.message);
}

closeFileDescriptor⁹⁺

static closeFileDescriptor(fd: number): void

Closes a file descriptor. This API is a static method.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
fd	number	Yes	File descriptor to close.

Example

import fs from '@ohos.file.fs';
import { BusinessError } from '@ohos.base';

let filePath = "path/to/file";
let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE|fs.OpenMode.CREATE);
try {
  rpc.MessageSequence.closeFileDescriptor(file.fd);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc close file descriptor fail, errorCode " + e.code);
  console.info("rpc close file descriptor fail, errorMessage" + e.message);
}

dupFileDescriptor

static dupFileDescriptor(fd: number) :number

Duplicates a file descriptor. This API is a static method.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
fd	number	Yes	File descriptor to duplicate.

Return value

Type	Description
number	New file descriptor.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900013	call os dup function failed

Example

import fs from '@ohos.file.fs';
import { BusinessError } from '@ohos.base';

let filePath = "path/to/file";
let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE|fs.OpenMode.CREATE);
try {
  rpc.MessageSequence.dupFileDescriptor(file.fd);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc dup file descriptor fail, errorCode " + e.code);
  console.info("rpc dup file descriptor fail, errorMessage" + e.message);
}

containFileDescriptors

containFileDescriptors(): boolean

Checks whether this MessageSequence object contains file descriptors.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
boolean	Returns true if the MessageSequence object contains file descriptors; returns false otherwise.

Example

import fs from '@ohos.file.fs';
import { BusinessError } from '@ohos.base';

let sequence = new rpc.MessageSequence();
let filePath = "path/to/file";
let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE|fs.OpenMode.CREATE);
try {
  sequence.writeFileDescriptor(file.fd);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write file descriptor fail, errorCode " + e.code);
  console.info("rpc write file descriptor fail, errorMessage" + e.message);
}
try {
  let containFD = sequence.containFileDescriptors();
  console.log("RpcTest: sequence after write fd containFd result is : " + containFD);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc contain file descriptor fail, errorCode " + e.code);
  console.info("rpc contain file descriptor fail, errorMessage" + e.message);
}

writeFileDescriptor

writeFileDescriptor(fd: number): void

Writes a file descriptor to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
fd	number	Yes	File descriptor to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import fs from '@ohos.file.fs';
import { BusinessError } from '@ohos.base';

let sequence = new rpc.MessageSequence();
let filePath = "path/to/file";
let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE|fs.OpenMode.CREATE);
try {
  sequence.writeFileDescriptor(file.fd);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write file descriptor fail, errorCode " + e.code);
  console.info("rpc write file descriptor fail, errorMessage" + e.message);
}

readFileDescriptor

readFileDescriptor(): number

Reads the file descriptor from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	File descriptor read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import fs from '@ohos.file.fs';
import { BusinessError } from '@ohos.base';

let sequence = new rpc.MessageSequence();
let filePath = "path/to/file";
let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE|fs.OpenMode.CREATE);
try {
  sequence.writeFileDescriptor(file.fd);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write file descriptor fail, errorCode " + e.code);
  console.info("rpc write file descriptor fail, errorMessage" + e.message);
}
try {
  let readFD = sequence.readFileDescriptor();
  console.log("RpcClient: readFileDescriptor is: " + readFD);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read file descriptor fail, errorCode " + e.code);
  console.info("rpc read file descriptor fail, errorMessage" + e.message);
}

writeAshmem

writeAshmem(ashmem: Ashmem): void

Writes an anonymous shared object to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
ashmem	Ashmem	Yes	Anonymous shared object to write.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900003	write to ashmem failed

Example

import { BusinessError } from '@ohos.base';

let sequence = new rpc.MessageSequence();
let ashmem: rpc.Ashmem|undefined = undefined;
try {
  ashmem = rpc.Ashmem.create("ashmem", 1024);
  try {
    sequence.writeAshmem(ashmem);
  } catch(error) {
    let e: BusinessError = error as BusinessError;
    console.info("rpc write ashmem fail, errorCode " + e.code);
    console.info("rpc write ashmem fail, errorMessage" + e.message);
  }
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc create ashmem fail, errorCode " + e.code);
  console.info("rpc creat ashmem fail, errorMessage" + e.message);
}

readAshmem

readAshmem(): Ashmem

Reads the anonymous shared object from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
Ashmem	Anonymous share object obtained.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900004	read from ashmem failed

Example

import { BusinessError } from '@ohos.base';

let sequence = new rpc.MessageSequence();
let ashmem: rpc.Ashmem|undefined = undefined;
try {
  ashmem = rpc.Ashmem.create("ashmem", 1024);
  try {
    sequence.writeAshmem(ashmem);
  } catch(error) {
    let e: BusinessError = error as BusinessError;
    console.info("rpc write ashmem fail, errorCode " + e.code);
    console.info("rpc write ashmem fail, errorMessage" + e.message);
  }
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc create ashmem fail, errorCode " + e.code);
  console.info("rpc creat ashmem fail, errorMessage" + e.message);
}
try {
  let readAshmem = sequence.readAshmem();
  console.log("RpcTest: read ashmem to result is : " + readAshmem);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read ashmem fail, errorCode " + e.code);
  console.info("rpc read ashmem fail, errorMessage" + e.message);
}

getRawDataCapacity

getRawDataCapacity(): number

Obtains the maximum amount of raw data that can be held by this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	128 MB, which is the maximum amount of raw data that can be held by this MessageSequence object.

Example

let sequence = new rpc.MessageSequence();
let result = sequence.getRawDataCapacity();
console.log("RpcTest: sequence get RawDataCapacity result is : " + result);

writeRawData

writeRawData(rawData: number[], size: number): void

Writes raw data to this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
rawData	number[]	Yes	Raw data to write.
size	number	Yes	Size of the raw data, in bytes.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900009	write data to message sequence failed

Example

import { BusinessError } from '@ohos.base';

let sequence = new rpc.MessageSequence();
let arr = [1, 2, 3, 4, 5];
try {
  sequence.writeRawData(arr, arr.length);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write rawdata fail, errorCode " + e.code);
  console.info("rpc write rawdata fail, errorMessage" + e.message);
}

readRawData

readRawData(size: number): number[]

Reads raw data from this MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
size	number	Yes	Size of the raw data to read.

Return value

Type	Description
number[]	Raw data obtained, in bytes.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900010	read data from message sequence failed

Example

import { BusinessError } from '@ohos.base';

let sequence = new rpc.MessageSequence();
let arr = [1, 2, 3, 4, 5];
try {
  sequence.writeRawData(arr, arr.length);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc write rawdata fail, errorCode " + e.code);
  console.info("rpc write rawdata fail, errorMessage" + e.message);
}
try {
  let result = sequence.readRawData(5);
  console.log("RpcTest: sequence read raw data result is : " + result);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc read rawdata fail, errorCode " + e.code);
  console.info("rpc read rawdata fail, errorMessage" + e.message);
}

MessageParcel^(deprecated)

This class is no longer maintained since API version 9. You are advised to use MessageSequence.

Provides APIs for reading and writing data in specific format. During RPC, the sender can use the write() method provided by MessageParcel to write data in specific format to a MessageParcel object. The receiver can use the read() method provided by MessageParcel to read data in specific format from a MessageParcel object. The data formats include basic data types and arrays, IPC objects, interface tokens, and custom sequenceable objects.

create

static create(): MessageParcel

Creates a MessageParcel object. This method is a static method.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
MessageParcel	MessageParcel object created.

Example

let data = rpc.MessageParcel.create();
console.log("RpcClient: data is " + data);

reclaim

reclaim(): void

Reclaims the MessageParcel object that is no longer used.

System capability: SystemCapability.Communication.IPC.Core

Example

let reply = rpc.MessageParcel.create();
reply.reclaim();

writeRemoteObject

writeRemoteObject(object: IRemoteObject): boolean

Serializes a remote object and writes it to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
object	IRemoteObject	Yes	Remote object to serialize and write to the MessageParcel object.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
}
let data = rpc.MessageParcel.create();
let testRemoteObject = new TestRemoteObject("testObject");
data.writeRemoteObject(testRemoteObject);

readRemoteObject

readRemoteObject(): IRemoteObject

Reads the remote object from this MessageParcel object. You can use this method to deserialize the MessageParcel object to generate an IRemoteObject. The remote objects are read in the order in which they are written to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
IRemoteObject	Remote object obtained.

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
}
let data = rpc.MessageParcel.create();
let testRemoteObject = new TestRemoteObject("testObject");
data.writeRemoteObject(testRemoteObject);
let proxy = data.readRemoteObject();
console.log("readRemoteObject is " + proxy);

writeInterfaceToken

writeInterfaceToken(token: string): boolean

Writes an interface token to this MessageParcel object. The remote object can use this interface token to verify the communication.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
token	string	Yes	Interface token to write.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeInterfaceToken("aaa");
console.log("RpcServer: writeInterfaceToken is " + result);

readInterfaceToken

readInterfaceToken(): string

Reads the interface token from this MessageParcel object. The interface token is read in the sequence in which it is written to the MessageParcel object. The local object can use it to verify the communication.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	Interface token obtained.

Example

class Stub extends rpc.RemoteObject {
  onRemoteRequest(code: number, data: rpc.MessageParcel, reply: rpc.MessageParcel, option: rpc.MessageOption): boolean {
    let interfaceToken = data.readInterfaceToken();
    console.log("RpcServer: interfaceToken is " + interfaceToken);
    return true;
  }
}

getSize

getSize(): number

Obtains the data size of this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Size of the MessageParcel object obtained, in bytes.

Example

let data = rpc.MessageParcel.create();
let size = data.getSize();
console.log("RpcClient: size is " + size);

getCapacity

getCapacity(): number

Obtains the capacity of this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	MessageParcel capacity obtained, in bytes.

Example

let data = rpc.MessageParcel.create();
let result = data.getCapacity();
console.log("RpcClient: capacity is " + result);

setSize

setSize(size: number): boolean

Sets the size of data contained in this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
size	number	Yes	Data size to set, in bytes.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let setSize = data.setSize(16);
console.log("RpcClient: setSize is " + setSize);

setCapacity

setCapacity(size: number): boolean

Sets the storage capacity of this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
size	number	Yes	Storage capacity to set, in bytes.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.setCapacity(100);
console.log("RpcClient: setCapacity is " + result);

getWritableBytes

getWritableBytes(): number

Obtains the writable capacity of this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	MessageParcel writable capacity obtained, in bytes.

Example

class Stub extends rpc.RemoteObject {
  onRemoteRequest(code: number, data: rpc.MessageParcel, reply: rpc.MessageParcel, option: rpc.MessageOption): boolean {
    let getWritableBytes = data.getWritableBytes();
    console.log("RpcServer: getWritableBytes is " + getWritableBytes);
    return true;
  }
}

getReadableBytes

getReadableBytes(): number

Obtains the readable capacity of this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	MessageParcel object readable capacity, in bytes.

Example

class Stub extends rpc.RemoteObject {
  onRemoteRequest(code: number, data: rpc.MessageParcel, reply: rpc.MessageParcel, option: rpc.MessageOption): boolean {
    let result = data.getReadableBytes();
    console.log("RpcServer: getReadableBytes is " + result);
    return true;
  }
}

getReadPosition

getReadPosition(): number

Obtains the read position of this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Current read position of the MessageParcel object.

Example

let data = rpc.MessageParcel.create();
let readPos = data.getReadPosition();
console.log("RpcClient: readPos is " + readPos);

getWritePosition

getWritePosition(): number

Obtains the write position of this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Current write position of the MessageParcel object.

Example

let data = rpc.MessageParcel.create();
data.writeInt(10);
let bwPos = data.getWritePosition();
console.log("RpcClient: bwPos is " + bwPos);

rewindRead

rewindRead(pos: number): boolean

Moves the read pointer to the specified position.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
pos	number	Yes	Position from which data is to read.

Return value

Type	Description
boolean	Returns true if the read position changes; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
data.writeInt(12);
data.writeString("parcel");
let number = data.readInt();
console.log("RpcClient: number is " + number);
data.rewindRead(0);
let number2 = data.readInt();
console.log("RpcClient: rewindRead is " + number2);

rewindWrite

rewindWrite(pos: number): boolean

Moves the write pointer to the specified position.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
pos	number	Yes	Position from which data is to write.

Return value

Type	Description
boolean	Returns true if the write position changes; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
data.writeInt(4);
data.rewindWrite(0);
data.writeInt(5);
let number = data.readInt();
console.log("RpcClient: rewindWrite is: " + number);

writeByte

writeByte(val: number): boolean

Writes a Byte value to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Byte value to write.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeByte(2);
console.log("RpcClient: writeByte is: " + result);

readByte

readByte(): number

Reads the Byte value from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Byte value read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeByte(2);
console.log("RpcClient: writeByte is: " + result);
let ret = data.readByte();
console.log("RpcClient: readByte is: " + ret);

writeShort

writeShort(val: number): boolean

Writes a Short int value to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Short int value to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeShort(8);
console.log("RpcClient: writeShort is: " + result);

readShort

readShort(): number

Reads the Short int value from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Short int value read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeShort(8);
console.log("RpcClient: writeShort is: " + result);
let ret = data.readShort();
console.log("RpcClient: readShort is: " + ret);

writeInt

writeInt(val: number): boolean

Writes an Int value to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Int value to write.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeInt(10);
console.log("RpcClient: writeInt is " + result);

readInt

readInt(): number

Reads the Int value from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Int value read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeInt(10);
console.log("RpcClient: writeInt is " + result);
let ret = data.readInt();
console.log("RpcClient: readInt is " + ret);

writeLong

writeLong(val: number): boolean

Writes a Long int value to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Long int value to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeLong(10000);
console.log("RpcClient: writeLong is " + result);

readLong

readLong(): number

Reads the Long int value from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Long int value read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeLong(10000);
console.log("RpcClient: writeLong is " + result);
let ret = data.readLong();
console.log("RpcClient: readLong is " + ret);

writeFloat

writeFloat(val: number): boolean

Writes a Float value to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Float value to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeFloat(1.2);
console.log("RpcClient: writeFloat is " + result);

readFloat

readFloat(): number

Reads the Float value from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Float value read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeFloat(1.2);
console.log("RpcClient: writeFloat is " + result);
let ret = data.readFloat();
console.log("RpcClient: readFloat is " + ret);

writeDouble

writeDouble(val: number): boolean

Writes a Double value to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Double value to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeDouble(10.2);
console.log("RpcClient: writeDouble is " + result);

readDouble

readDouble(): number

Reads the Double value from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Double value read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeDouble(10.2);
console.log("RpcClient: writeDouble is " + result);
let ret = data.readDouble();
console.log("RpcClient: readDouble is " + ret);

writeBoolean

writeBoolean(val: boolean): boolean

Writes a Boolean value to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	boolean	Yes	Boolean value to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeBoolean(false);
console.log("RpcClient: writeBoolean is " + result);

readBoolean

readBoolean(): boolean

Reads the Boolean value from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
boolean	Boolean value read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeBoolean(false);
console.log("RpcClient: writeBoolean is " + result);
let ret = data.readBoolean();
console.log("RpcClient: readBoolean is " + ret);

writeChar

writeChar(val: number): boolean

Writes a Char value to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	number	Yes	Char value to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeChar(97);
console.log("RpcClient: writeChar is " + result);

readChar

readChar(): number

Reads the Char value from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Char value read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeChar(97);
console.log("RpcClient: writeChar is " + result);
let ret = data.readChar();
console.log("RpcClient: readChar is " + ret);

writeString

writeString(val: string): boolean

Writes a string to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	string	Yes	String to write. The length of the string must be less than 40960 bytes.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeString('abc');
console.log("RpcClient: writeString  is " + result);

readString

readString(): string

Reads the string from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	String read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeString('abc');
console.log("RpcClient: writeString  is " + result);
let ret = data.readString();
console.log("RpcClient: readString is " + ret);

writeSequenceable

writeSequenceable(val: Sequenceable): boolean

Writes a sequenceable object to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
val	Sequenceable	Yes	Sequenceable object to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

class MySequenceable implements rpc.Sequenceable {
  num: number = 0;
  str: string = '';
  constructor(num: number, str: string) {
    this.num = num;
    this.str = str;
  }
  marshalling(messageParcel: rpc.MessageParcel): boolean {
    messageParcel.writeInt(this.num);
    messageParcel.writeString(this.str);
    return true;
  }
  unmarshalling(messageParcel: rpc.MessageParcel): boolean {
    this.num = messageParcel.readInt();
    this.str = messageParcel.readString();
    return true;
  }
}
let sequenceable = new MySequenceable(1, "aaa");
let data = rpc.MessageParcel.create();
let result = data.writeSequenceable(sequenceable);
console.log("RpcClient: writeSequenceable is " + result);

readSequenceable

readSequenceable(dataIn: Sequenceable): boolean

Reads member variables from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	Sequenceable	Yes	Object that reads member variables from the MessageParcel object.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

class MySequenceable implements rpc.Sequenceable {
  num: number = 0;
  str: string = '';
  constructor(num: number, str: string) {
    this.num = num;
    this.str = str;
  }
  marshalling(messageParcel: rpc.MessageParcel): boolean {
    messageParcel.writeInt(this.num);
    messageParcel.writeString(this.str);
    return true;
  }
  unmarshalling(messageParcel: rpc.MessageParcel): boolean {
    this.num = messageParcel.readInt();
    this.str = messageParcel.readString();
    return true;
  }
}
let sequenceable = new MySequenceable(1, "aaa");
let data = rpc.MessageParcel.create();
let result = data.writeSequenceable(sequenceable);
console.log("RpcClient: writeSequenceable is " + result);
let ret = new MySequenceable(0, "");
let result2 = data.readSequenceable(ret);
console.log("RpcClient: writeSequenceable is " + result2);

writeByteArray

writeByteArray(byteArray: number[]): boolean

Writes a byte array to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
byteArray	number[]	Yes	Byte array to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let ByteArrayVar = [1, 2, 3, 4, 5];
let result = data.writeByteArray(ByteArrayVar);
console.log("RpcClient: writeByteArray is " + result);

readByteArray

readByteArray(dataIn: number[]): void

Reads a byte array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Byte array to read.

Example

let data = rpc.MessageParcel.create();
let ByteArrayVar = [1, 2, 3, 4, 5];
let result = data.writeByteArray(ByteArrayVar);
console.log("RpcClient: writeByteArray is " + result);
let array: Array<number> = new Array(5);
data.readByteArray(array);

readByteArray

readByteArray(): number[]

Reads the byte array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	Byte array read.

Example

let data = rpc.MessageParcel.create();
let ByteArrayVar = [1, 2, 3, 4, 5];
let result = data.writeByteArray(ByteArrayVar);
console.log("RpcClient: writeByteArray is " + result);
let array = data.readByteArray();
console.log("RpcClient: readByteArray is " + array);

writeShortArray

writeShortArray(shortArray: number[]): boolean

Writes a short array to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
shortArray	number[]	Yes	Short array to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeShortArray([11, 12, 13]);
console.log("RpcClient: writeShortArray is " + result);

readShortArray

readShortArray(dataIn: number[]): void

Reads a short array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Short array to read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeShortArray([11, 12, 13]);
console.log("RpcClient: writeShortArray is " + result);
let array: Array<number> = new Array(3);
data.readShortArray(array);

readShortArray

readShortArray(): number[]

Reads the short array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	Short array read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeShortArray([11, 12, 13]);
console.log("RpcClient: writeShortArray is " + result);
let array = data.readShortArray();
console.log("RpcClient: readShortArray is " + array);

writeIntArray

writeIntArray(intArray: number[]): boolean

Writes an integer array to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
intArray	number[]	Yes	Integer array to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeIntArray([100, 111, 112]);
console.log("RpcClient: writeIntArray is " + result);

readIntArray

readIntArray(dataIn: number[]): void

Reads an integer array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Integer array to read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeIntArray([100, 111, 112]);
console.log("RpcClient: writeIntArray is " + result);
let array: Array<number> = new Array(3);
data.readIntArray(array);

readIntArray

readIntArray(): number[]

Reads the integer array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	Integer array read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeIntArray([100, 111, 112]);
console.log("RpcClient: writeIntArray is " + result);
let array = data.readIntArray();
console.log("RpcClient: readIntArray is " + array);

writeLongArray

writeLongArray(longArray: number[]): boolean

Writes a long array to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
longArray	number[]	Yes	Long array to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeLongArray([1111, 1112, 1113]);
console.log("RpcClient: writeLongArray is " + result);

readLongArray

readLongArray(dataIn: number[]): void

Reads a long array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Long array to read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeLongArray([1111, 1112, 1113]);
console.log("RpcClient: writeLongArray is " + result);
let array: Array<number> = new Array(3);
data.readLongArray(array);

readLongArray

readLongArray(): number[]

Reads the long array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	Long array read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeLongArray([1111, 1112, 1113]);
console.log("RpcClient: writeLongArray is " + result);
let array = data.readLongArray();
console.log("RpcClient: readLongArray is " + array);

writeFloatArray

writeFloatArray(floatArray: number[]): boolean

Writes a FloatArray to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
floatArray	number[]	Yes	Floating-point array to write. The system processes Float data as that of the Double type. Therefore, the total number of bytes occupied by a FloatArray must be calculated as the Double type.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeFloatArray([1.2, 1.3, 1.4]);
console.log("RpcClient: writeFloatArray is " + result);

readFloatArray

readFloatArray(dataIn: number[]): void

Reads a FloatArray from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Floating-point array to read. The system processes Float data as that of the Double type. Therefore, the total number of bytes occupied by a FloatArray must be calculated as the Double type.

Example

let data = rpc.MessageParcel.create();
let result = data.writeFloatArray([1.2, 1.3, 1.4]);
console.log("RpcClient: writeFloatArray is " + result);
let array: Array<number> = new Array(3);
data.readFloatArray(array);

readFloatArray

readFloatArray(): number[]

Reads the FloatArray from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	FloatArray read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeFloatArray([1.2, 1.3, 1.4]);
console.log("RpcClient: writeFloatArray is " + result);
let array = data.readFloatArray();
console.log("RpcClient: readFloatArray is " + array);

writeDoubleArray

writeDoubleArray(doubleArray: number[]): boolean

Writes a DoubleArray to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
doubleArray	number[]	Yes	DoubleArray to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeDoubleArray([11.1, 12.2, 13.3]);
console.log("RpcClient: writeDoubleArray is " + result);

readDoubleArray

readDoubleArray(dataIn: number[]): void

Reads a DoubleArray from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	DoubleArray to read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeDoubleArray([11.1, 12.2, 13.3]);
console.log("RpcClient: writeDoubleArray is " + result);
let array: Array<number> = new Array(3);
data.readDoubleArray(array);

readDoubleArray

readDoubleArray(): number[]

Reads the DoubleArray from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	DoubleArray read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeDoubleArray([11.1, 12.2, 13.3]);
console.log("RpcClient: writeDoubleArray is " + result);
let array = data.readDoubleArray();
console.log("RpcClient: readDoubleArray is " + array);

writeBooleanArray

writeBooleanArray(booleanArray: boolean[]): boolean

Writes a Boolean array to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
booleanArray	boolean[]	Yes	Boolean array to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeBooleanArray([false, true, false]);
console.log("RpcClient: writeBooleanArray is " + result);

readBooleanArray

readBooleanArray(dataIn: boolean[]): void

Reads a Boolean array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	boolean[]	Yes	Boolean array to read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeBooleanArray([false, true, false]);
console.log("RpcClient: writeBooleanArray is " + result);
let array: Array<boolean> = new Array(3);
data.readBooleanArray(array);

readBooleanArray

readBooleanArray(): boolean[]

Reads the Boolean array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
boolean[]	Boolean array read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeBooleanArray([false, true, false]);
console.log("RpcClient: writeBooleanArray is " + result);
let array = data.readBooleanArray();
console.log("RpcClient: readBooleanArray is " + array);

writeCharArray

writeCharArray(charArray: number[]): boolean

Writes a character array to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
charArray	number[]	Yes	Character array to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeCharArray([97, 98, 88]);
console.log("RpcClient: writeCharArray is " + result);

readCharArray

readCharArray(dataIn: number[]): void

Reads a character array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	number[]	Yes	Character array to read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeCharArray([97, 98, 99]);
console.log("RpcClient: writeCharArray is " + result);
let array: Array<number> = new Array(3);
data.readCharArray(array);

readCharArray

readCharArray(): number[]

Reads the character array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number[]	Character array read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeCharArray([97, 98, 99]);
console.log("RpcClient: writeCharArray is " + result);
let array = data.readCharArray();
console.log("RpcClient: readCharArray is " + array);

writeStringArray

writeStringArray(stringArray: string[]): boolean

Writes a string array to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
stringArray	string[]	Yes	String array to write. The length of a single element in the array must be less than 40960 bytes.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let data = rpc.MessageParcel.create();
let result = data.writeStringArray(["abc", "def"]);
console.log("RpcClient: writeStringArray is " + result);

readStringArray

readStringArray(dataIn: string[]): void

Reads a string array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	string[]	Yes	String array to read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeStringArray(["abc", "def"]);
console.log("RpcClient: writeStringArray is " + result);
let array: Array<string> = new Array(2);
data.readStringArray(array);

readStringArray

readStringArray(): string[]

Reads the string array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string[]	String array read.

Example

let data = rpc.MessageParcel.create();
let result = data.writeStringArray(["abc", "def"]);
console.log("RpcClient: writeStringArray is " + result);
let array = data.readStringArray();
console.log("RpcClient: readStringArray is " + array);

writeNoException⁸⁺

writeNoException(): void

Writes information to this MessageParcel object indicating that no exception occurred.

System capability: SystemCapability.Communication.IPC.Core

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
  onRemoteRequest(code: number, data: rpc.MessageParcel, reply: rpc.MessageParcel, option: rpc.MessageOption): boolean {
    if (code === 1) {
      console.log("RpcServer: onRemoteRequest called");
      reply.writeNoException();
      return true;
    } else {
      console.log("RpcServer: unknown code: " + code);
      return false;
    }
  }
}

readException⁸⁺

readException(): void

Reads the exception information from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, sendMessageRequest() of the proxy object is called to send a message.

let option = new rpc.MessageOption();
let data = rpc.MessageParcel.create();
let reply = rpc.MessageParcel.create();
data.writeInt(1);
data.writeString("hello");
proxy.sendRequest(1, data, reply, option)
    .then((result: rpc.SendRequestResult) => {
        if (result.errCode === 0) {
            console.log("sendRequest got result");
            result.reply.readException();
            let msg = result.reply.readString();
            console.log("RPCTest: reply msg: " + msg);
        } else {
            console.log("RPCTest: sendRequest failed, errCode: " + result.errCode);
        }
    }).catch((e: Error) => {
        console.log("RPCTest: sendRequest got exception: " + e.message);
    }).finally (() => {
        console.log("RPCTest: sendRequest ends, reclaim parcel");
        data.reclaim();
        reply.reclaim();
    });

writeSequenceableArray

writeSequenceableArray(sequenceableArray: Sequenceable[]): boolean

Writes a sequenceable array to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
sequenceableArray	Sequenceable[]	Yes	Sequenceable array to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

class MySequenceable implements rpc.Sequenceable {
  num: number = 0;
  str: string = '';
  constructor(num: number, str: string) {
    this.num = num;
    this.str = str;
  }
  marshalling(messageParcel: rpc.MessageParcel): boolean {
    messageParcel.writeInt(this.num);
    messageParcel.writeString(this.str);
    return true;
  }
  unmarshalling(messageParcel: rpc.MessageParcel): boolean {
    this.num = messageParcel.readInt();
    this.str = messageParcel.readString();
    return true;
  }
}
let sequenceable = new MySequenceable(1, "aaa");
let sequenceable2 = new MySequenceable(2, "bbb");
let sequenceable3 = new MySequenceable(3, "ccc");
let a = [sequenceable, sequenceable2, sequenceable3];
let data = rpc.MessageParcel.create();
let result = data.writeSequenceableArray(a);
console.log("RpcClient: writeSequenceableArray is " + result);

readSequenceableArray⁸⁺

readSequenceableArray(sequenceableArray: Sequenceable[]): void

Reads a sequenceable array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
sequenceableArray	Sequenceable[]	Yes	Sequenceable array to read.

Example

class MySequenceable implements rpc.Sequenceable {
  num: number = 0;
  str: string = '';
  constructor(num: number, str: string) {
    this.num = num;
    this.str = str;
  }
  marshalling(messageParcel: rpc.MessageParcel): boolean {
    messageParcel.writeInt(this.num);
    messageParcel.writeString(this.str);
    return true;
  }
  unmarshalling(messageParcel: rpc.MessageParcel): boolean {
    this.num = messageParcel.readInt();
    this.str = messageParcel.readString();
    return true;
  }
}
let sequenceable = new MySequenceable(1, "aaa");
let sequenceable2 = new MySequenceable(2, "bbb");
let sequenceable3 = new MySequenceable(3, "ccc");
let a = [sequenceable, sequenceable2, sequenceable3];
let data = rpc.MessageParcel.create();
let result = data.writeSequenceableArray(a);
console.log("RpcClient: writeSequenceableArray is " + result);
let b = [new MySequenceable(0, ""), new MySequenceable(0, ""), new MySequenceable(0, "")];
data.readSequenceableArray(b);

writeRemoteObjectArray⁸⁺

writeRemoteObjectArray(objectArray: IRemoteObject[]): boolean

Writes an array of IRemoteObject objects to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
objectArray	IRemoteObject[]	Yes	Array of IRemoteObject objects to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
    this.attachLocalInterface(this, descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
  asObject(): rpc.IRemoteObject {
    return this;
  }
}
let a = [new TestRemoteObject("testObject1"), new TestRemoteObject("testObject2"), new TestRemoteObject("testObject3")];
let data = rpc.MessageParcel.create();
let result = data.writeRemoteObjectArray(a);
console.log("RpcClient: writeRemoteObjectArray is " + result);

readRemoteObjectArray⁸⁺

readRemoteObjectArray(objects: IRemoteObject[]): void

Reads an IRemoteObject array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
objects	IRemoteObject[]	Yes	IRemoteObject array to read.

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
    this.attachLocalInterface(this, descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
  asObject(): rpc.IRemoteObject {
    return this;
  }
}
let a = [new TestRemoteObject("testObject1"), new TestRemoteObject("testObject2"), new TestRemoteObject("testObject3")];
let data = rpc.MessageParcel.create();
data.writeRemoteObjectArray(a);
let b: Array<rpc.IRemoteObject> = new Array(3);
data.readRemoteObjectArray(b);

readRemoteObjectArray⁸⁺

readRemoteObjectArray(): IRemoteObject[]

Reads the IRemoteObject array from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
IRemoteObject[]	IRemoteObject object array obtained.

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
    this.attachLocalInterface(this, descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
  asObject(): rpc.IRemoteObject {
    return this;
  }
}
let a = [new TestRemoteObject("testObject1"), new TestRemoteObject("testObject2"), new TestRemoteObject("testObject3")];
let data = rpc.MessageParcel.create();
let result = data.writeRemoteObjectArray(a);
console.log("RpcClient: readRemoteObjectArray is " + result);
let b = data.readRemoteObjectArray();
console.log("RpcClient: readRemoteObjectArray is " + b);

closeFileDescriptor⁸⁺

static closeFileDescriptor(fd: number): void

Closes a file descriptor. This API is a static method.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
fd	number	Yes	File descriptor to close.

Example

import fs from '@ohos.file.fs';

let filePath = "path/to/file";
let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE|fs.OpenMode.CREATE);
rpc.MessageParcel.closeFileDescriptor(file.fd);

dupFileDescriptor⁸⁺

static dupFileDescriptor(fd: number) :number

Duplicates a file descriptor. This API is a static method.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
fd	number	Yes	File descriptor to duplicate.

Return value

Type	Description
number	New file descriptor.

Example

import fs from '@ohos.file.fs';

let filePath = "path/to/file";
let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE|fs.OpenMode.CREATE);
rpc.MessageParcel.dupFileDescriptor(file.fd);

containFileDescriptors⁸⁺

containFileDescriptors(): boolean

Checks whether this MessageParcel object contains file descriptors.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
boolean	Returns true if the MessageParcel object contains file descriptors; returns false otherwise.

Example

import fs from '@ohos.file.fs';

let parcel = new rpc.MessageParcel();
let filePath = "path/to/file";
let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE|fs.OpenMode.CREATE);
let writeResult = parcel.writeFileDescriptor(file.fd);
console.log("RpcTest: parcel writeFd result is : " + writeResult);
let containFD = parcel.containFileDescriptors();
console.log("RpcTest: parcel after write fd containFd result is : " + containFD);

writeFileDescriptor⁸⁺

writeFileDescriptor(fd: number): boolean

Writes a file descriptor to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
fd	number	Yes	File descriptor to write.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

import fs from '@ohos.file.fs';

let parcel = new rpc.MessageParcel();
let filePath = "path/to/file";
let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE|fs.OpenMode.CREATE);
let writeResult = parcel.writeFileDescriptor(file.fd);
console.log("RpcTest: parcel writeFd result is : " + writeResult);

readFileDescriptor⁸⁺

readFileDescriptor(): number

Reads the file descriptor from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	File descriptor read.

Example

import fs from '@ohos.file.fs';

let parcel = new rpc.MessageParcel();
let filePath = "path/to/file";
let file = fs.openSync(filePath, fs.OpenMode.READ_WRITE|fs.OpenMode.CREATE);
let writeResult = parcel.writeFileDescriptor(file.fd);
let readFD = parcel.readFileDescriptor();
console.log("RpcTest: parcel read fd is : " + readFD);

writeAshmem⁸⁺

writeAshmem(ashmem: Ashmem): boolean

Writes an anonymous shared object to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
ashmem	Ashmem	Yes	Anonymous shared object to write.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let parcel = new rpc.MessageParcel();
let ashmem = rpc.Ashmem.createAshmem("ashmem", 1024);
let isWriteSuccess = parcel.writeAshmem(ashmem);
console.log("RpcTest: write ashmem to result is : " + isWriteSuccess);

readAshmem⁸⁺

readAshmem(): Ashmem

Reads the anonymous shared object from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
Ashmem	Anonymous share object obtained.

Example

let parcel = new rpc.MessageParcel();
let ashmem = rpc.Ashmem.createAshmem("ashmem", 1024);
let isWriteSuccess = parcel.writeAshmem(ashmem);
console.log("RpcTest: write ashmem to result is : " + isWriteSuccess);
let readAshmem = parcel.readAshmem();
console.log("RpcTest: read ashmem to result is : " + readAshmem);

getRawDataCapacity⁸⁺

getRawDataCapacity(): number

Obtains the maximum amount of raw data that can be held by this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	128 MB, which is the maximum amount of raw data that can be held by this MessageParcel object.

Example

let parcel = new rpc.MessageParcel();
let result = parcel.getRawDataCapacity();
console.log("RpcTest: parcel get RawDataCapacity result is : " + result);

writeRawData⁸⁺

writeRawData(rawData: number[], size: number): boolean

Writes raw data to this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
rawData	number[]	Yes	Raw data to write.
size	number	Yes	Size of the raw data, in bytes.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let parcel = new rpc.MessageParcel();
let arr = [1, 2, 3, 4, 5];
let isWriteSuccess = parcel.writeRawData(arr, arr.length);
console.log("RpcTest: parcel write raw data result is : " + isWriteSuccess);

readRawData⁸⁺

readRawData(size: number): number[]

Reads raw data from this MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
size	number	Yes	Size of the raw data to read.

Return value

Type	Description
number[]	Raw data obtained, in bytes.

Example

let parcel = new rpc.MessageParcel();
let arr = [1, 2, 3, 4, 5];
let isWriteSuccess = parcel.writeRawData(arr, arr.length);
console.log("RpcTest: parcel write raw data result is : " + isWriteSuccess);
let result = parcel.readRawData(5);
console.log("RpcTest: parcel read raw data result is : " + result);

Parcelable⁹⁺

Writes an object to a MessageSequence and reads it from the MessageSequence during IPC.

marshalling

marshalling(dataOut: MessageSequence): boolean

Marshals this Parcelable object into a MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataOut	MessageSequence	Yes	MessageSequence object to which the Parcelable object is to be marshaled.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

class MyParcelable implements rpc.Parcelable {
  num: number = 0;
  str: string = '';
  constructor(num: number, str: string) {
    this.num = num;
    this.str = str;
  }
  marshalling(messageSequence: rpc.MessageSequence): boolean {
    messageSequence.writeInt(this.num);
    messageSequence.writeString(this.str);
    return true;
  }
  unmarshalling(messageSequence: rpc.MessageSequence): boolean {
    this.num = messageSequence.readInt();
    this.str = messageSequence.readString();
    return true;
  }
}
let parcelable = new MyParcelable(1, "aaa");
let data = rpc.MessageSequence.create();
let result = data.writeParcelable(parcelable);
console.log("RpcClient: writeParcelable is " + result);
let ret = new MyParcelable(0, "");
let result2 = data.readParcelable(ret);
console.log("RpcClient: readParcelable is " + result2);

unmarshalling

unmarshalling(dataIn: MessageSequence): boolean

Unmarshals this Parcelable object from a MessageSequence object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	MessageSequence	Yes	MessageSequence object from which the Parcelable object is to be unmarshaled.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

class MyParcelable implements rpc.Parcelable {
  num: number = 0;
  str: string = '';
  constructor(num: number, str: string) {
    this.num = num;
    this.str = str;
  }
  marshalling(messageSequence: rpc.MessageSequence): boolean {
    messageSequence.writeInt(this.num);
    messageSequence.writeString(this.str);
    return true;
  }
  unmarshalling(messageSequence: rpc.MessageSequence): boolean {
    this.num = messageSequence.readInt();
    this.str = messageSequence.readString();
    return true;
  }
}
let parcelable = new MyParcelable(1, "aaa");
let data = rpc.MessageSequence.create();
let result = data.writeParcelable(parcelable);
console.log("RpcClient: writeParcelable is " + result);
let ret = new MyParcelable(0, "");
let result2 = data.readParcelable(ret);
console.log("RpcClient: readParcelable is " + result2);

Sequenceable^(deprecated)

This class is no longer maintained since API version 9. You are advised to use the Parcelable.

Writes objects of classes to a MessageParcel and reads them from the MessageParcel during IPC.

marshalling

marshalling(dataOut: MessageParcel): boolean

Marshals the sequenceable object into a MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataOut	MessageParcel	Yes	MessageParcel object to which the sequenceable object is to be marshaled.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

class MySequenceable implements rpc.Sequenceable {
  num: number = 0;
  str: string = '';
  constructor(num: number, str: string) {
    this.num = num;
    this.str = str;
  }
  marshalling(messageParcel: rpc.MessageParcel): boolean {
    messageParcel.writeInt(this.num);
    messageParcel.writeString(this.str);
    return true;
  }
  unmarshalling(messageParcel: rpc.MessageParcel): boolean {
    this.num = messageParcel.readInt();
    this.str = messageParcel.readString();
    return true;
  }
}
let sequenceable = new MySequenceable(1, "aaa");
let data = rpc.MessageParcel.create();
let result = data.writeSequenceable(sequenceable);
console.log("RpcClient: writeSequenceable is " + result);
let ret = new MySequenceable(0, "");
let result2 = data.readSequenceable(ret);
console.log("RpcClient: readSequenceable is " + result2);

unmarshalling

unmarshalling(dataIn: MessageParcel): boolean

Unmarshals this sequenceable object from a MessageParcel object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
dataIn	MessageParcel	Yes	MessageParcel object in which the sequenceable object is to be unmarshaled.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

class MySequenceable implements rpc.Sequenceable {
  num: number = 0;
  str: string = '';
  constructor(num: number, str: string) {
    this.num = num;
    this.str = str;
  }
  marshalling(messageParcel: rpc.MessageParcel): boolean {
    messageParcel.writeInt(this.num);
    messageParcel.writeString(this.str);
    return true;
  }
  unmarshalling(messageParcel: rpc.MessageParcel): boolean {
    this.num = messageParcel.readInt();
    this.str = messageParcel.readString();
    return true;
  }
}
let sequenceable = new MySequenceable(1, "aaa");
let data = rpc.MessageParcel.create();
let result = data.writeSequenceable(sequenceable);
console.log("RpcClient: writeSequenceable is " + result);
let ret = new MySequenceable(0, "");
let result2 = data.readSequenceable(ret);
console.log("RpcClient: readSequenceable is " + result2);

IRemoteBroker

Provides the holder of a remote proxy object.

asObject

asObject(): IRemoteObject

Obtains a proxy or remote object. This API must be implemented by its derived classes.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
IRemoteObject	Returns the RemoteObject if it is the caller; returns the IRemoteObject, the holder of this RemoteProxy object, if the caller is a RemoteProxy object.

Example

class TestAbility extends rpc.RemoteObject {
  asObject() {
    return this;
  }
}
let remoteObject = new TestAbility("testObject").asObject();

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";

import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want  = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, asObject() of the proxy object is called to obtain the proxy or remote object.

class TestProxy {
  remote: rpc.RemoteObject;
  constructor(remote: rpc.RemoteObject) {
    this.remote = remote;
  }
  asObject() {
    return this.remote;
  }
}
let iRemoteObject = new TestProxy(proxy).asObject();

DeathRecipient

Subscribes to death notifications of a remote object. When the remote object is dead, the local end will receive a notification and onRemoteDied will be called. A remote object is dead when the process holding the object is terminated or the device of the remote object is shut down or restarted. If the local and remote objects belong to different devices, the remote object is dead when the device holding the remote object is detached from the network.

onRemoteDied

onRemoteDied(): void

Called to perform subsequent operations when a death notification of the remote object is received.

System capability: SystemCapability.Communication.IPC.Core

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}

RequestResult⁹⁺

Defines the response to the request.

System capability: SystemCapability.Communication.IPC.Core

Name	Type	Readable	Writable	Description
errCode	number	Yes	No	Error code.
code	number	Yes	No	Message code.
data	MessageSequence	Yes	No	MessageSequence object sent to the remote process.
reply	MessageSequence	Yes	No	MessageSequence object returned by the remote process.

SendRequestResult^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use RequestResult.

Defines the response to the request.

System capability: SystemCapability.Communication.IPC.Core

Name	Type	Readable	Writable	Description
errCode	number	Yes	No	Error code.
code	number	Yes	No	Message code.
data	MessageParcel	Yes	No	MessageParcel object sent to the remote process.
reply	MessageParcel	Yes	No	MessageParcel object returned by the remote process.

IRemoteObject

Provides methods to query of obtain interface descriptors, add or delete death notifications, dump object status to specific files, and send messages.

getLocalInterface⁹⁺

getLocalInterface(descriptor: string): IRemoteBroker

Obtains the interface descriptor.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
descriptor	string	Yes	Interface descriptor.

Return value

Type	Description
IRemoteBroker	IRemoteBroker object bound to the specified interface token.

queryLocalInterface^(deprecated)

This API is no longer maintained since API version 9. You are advised to use getLocalInterface.

queryLocalInterface(descriptor: string): IRemoteBroker

Queries the interface descriptor.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
descriptor	string	Yes	Interface descriptor.

Return value

Type	Description
IRemoteBroker	IRemoteBroker object bound to the specified interface token.

sendRequest^(deprecated)

This API is no longer maintained since API version 9. You are advised to use sendMessageRequest.

sendRequest(code: number, data: MessageParcel, reply: MessageParcel, options: MessageOption): boolean

Sends a MessageParcel message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a promise will be fulfilled immediately and the reply message does not contain any content. If synchronous mode is set in options , a promise will be fulfilled when the response to sendRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageParcel	Yes	MessageParcel object holding the data to send.
reply	MessageParcel	Yes	MessageParcel object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.

Return value

Type	Description
boolean	Returns true if the message is sent successfully; returns false otherwise.

sendRequest^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use sendMessageRequest.

sendRequest(code: number, data: MessageParcel, reply: MessageParcel, options: MessageOption): Promise<SendRequestResult>

Sends a MessageParcel message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a promise will be fulfilled immediately and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a promise will be fulfilled when the response to sendRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageParcel	Yes	MessageParcel object holding the data to send.
reply	MessageParcel	Yes	MessageParcel object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.

Return value

Type	Description
Promise<SendRequestResult>	Promise used to return the sendRequestResult object.

sendMessageRequest⁹⁺

sendMessageRequest(code: number, data: MessageSequence, reply: MessageSequence, options: MessageOption): Promise<RequestResult>

Sends a MessageSequence message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a promise will be fulfilled immediately and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a promise will be fulfilled when the response to sendMessageRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageSequence	Yes	MessageSequence object holding the data to send.
reply	MessageSequence	Yes	MessageSequence object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.

Return value

Type	Description
Promise<RequestResult>	Promise used to return the requestResult object.

sendMessageRequest⁹⁺

sendMessageRequest(code: number, data: MessageSequence, reply: MessageSequence, options: MessageOption, callback: AsyncCallback<RequestResult>): void

Sends a MessageSequence message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a callback will be called immediately, and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a callback will be invoked when the response to sendRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageSequence	Yes	MessageSequence object holding the data to send.
reply	MessageSequence	Yes	MessageSequence object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.
callback	AsyncCallback<RequestResult>	Yes	Callback for receiving the sending result.

sendRequest^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use sendMessageRequest.

sendRequest(code: number, data: MessageParcel, reply: MessageParcel, options: MessageOption, callback: AsyncCallback<SendRequestResult>): void

Sends a MessageParcel message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a callback will be called immediately, and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a callback will be invoked when the response to sendRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageParcel	Yes	MessageParcel object holding the data to send.
reply	MessageParcel	Yes	MessageParcel object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.
callback	AsyncCallback<SendRequestResult>	Yes	Callback for receiving the sending result.

registerDeathRecipient⁹⁺

registerDeathRecipient(recipient: DeathRecipient, flags: number): void

Registers a callback for receiving death notifications of the remote object. The callback will be called if the remote object process matching the RemoteProxy object is killed.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
recipient	DeathRecipient	Yes	Callback to register.
flags	number	Yes	Flag of the death notification.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900008	proxy or remote object is invalid

addDeathrecipient^(deprecated)

This API is no longer maintained since API version 9. You are advised to use registerDeathRecipient.

addDeathRecipient(recipient: DeathRecipient, flags: number): boolean

Adds a callback for receiving death notifications of the remote object. This method is called if the remote object process matching the RemoteProxy object is killed.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
recipient	DeathRecipient	Yes	Callback to add.
flags	number	Yes	Flag of the death notification.

Return value

Type	Description
boolean	Returns true if the callback is added successfully; returns false otherwise.

unregisterDeathRecipient⁹⁺

unregisterDeathRecipient(recipient: DeathRecipient, flags: number): void

Unregisters the callback used to receive death notifications of the remote object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
recipient	DeathRecipient	Yes	Callback to unregister.
flags	number	Yes	Flag of the death notification.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900008	proxy or remote object is invalid

removeDeathRecipient^(deprecated)

This API is no longer maintained since API version 9. You are advised to use unregisterDeathRecipient.

removeDeathRecipient(recipient: DeathRecipient, flags: number): boolean

Removes the callback used to receive death notifications of the remote object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
recipient	DeathRecipient	Yes	Callback to remove.
flags	number	Yes	Flag of the death notification.

Return value

Type	Description
boolean	Returns true if the callback is removed; returns false otherwise.

getDescriptor⁹⁺

getDescriptor(): string

Obtains the interface descriptor (which is a string) of this object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	Interface descriptor obtained.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900008	proxy or remote object is invalid

getInterfaceDescriptor^(deprecated)

This API is no longer maintained since API version 9. You are advised to use getDescriptor.

getInterfaceDescriptor(): string

Obtains the interface descriptor (which is a string) of this object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	Interface descriptor obtained.

isObjectDead

isObjectDead(): boolean

Checks whether this object is dead.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
boolean	Returns true if the object is dead; returns false otherwise.

RemoteProxy

Provides APIs to implement IRemoteObject.

System capability: SystemCapability.Communication.IPC.Core

Name	Value	Description
PING_TRANSACTION	1599098439 (0x5f504e47)	Internal instruction code used to test whether the IPC service is normal.
DUMP_TRANSACTION	1598311760 (0x5f444d50)	Internal instruction code used to obtain the internal status of the binder.
INTERFACE_TRANSACTION	1598968902 (0x5f4e5446)	Internal instruction code used to obtain the remote interface token.
MIN_TRANSACTION_ID	1 (0x00000001)	Minimum valid instruction code.
MAX_TRANSACTION_ID	16777215 (0x00FFFFFF)	Maximum valid instruction code.

sendRequest^(deprecated)

This API is no longer maintained since API version 9. You are advised to use sendMessageRequest.

sendRequest(code: number, data: MessageParcel, reply: MessageParcel, options: MessageOption): boolean

Sends a MessageParcel message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a promise will be fulfilled immediately and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a promise will be fulfilled when the response to sendRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageParcel	Yes	MessageParcel object holding the data to send.
reply	MessageParcel	Yes	MessageParcel object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.

Return value

Type	Description
boolean	Returns true if the message is sent successfully; returns false otherwise.

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";

import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
   onConnect: (elementName, remoteProxy) => {
      console.log("RpcClient: js onConnect called.");
      proxy = remoteProxy;
   },
   onDisconnect: (elementName) => {
      console.log("RpcClient: onDisconnect");
   },
   onFailed: () => {
      console.log("RpcClient: onFailed");
   }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, sendMessageRequest() of the proxy object is called to send a message.

let option = new rpc.MessageOption();
let data = rpc.MessageParcel.create();
let reply = rpc.MessageParcel.create();
data.writeInt(1);
data.writeString("hello");
let ret: boolean = proxy.sendRequest(1, data, reply, option);
if (ret) {
  console.log("sendRequest got result");
  let msg = reply.readString();
  console.log("RPCTest: reply msg: " + msg);
} else {
  console.log("RPCTest: sendRequest failed");
}
console.log("RPCTest: sendRequest ends, reclaim parcel");
data.reclaim();
reply.reclaim();

sendMessageRequest⁹⁺

sendMessageRequest(code: number, data: MessageSequence, reply: MessageSequence, options: MessageOption): Promise<RequestResult>

Sends a MessageSequence message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a promise will be fulfilled immediately and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a promise will be fulfilled when the response to sendMessageRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageSequence	Yes	MessageSequence object holding the data to send.
reply	MessageSequence	Yes	MessageSequence object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.

Return value

Type	Description
Promise<RequestResult>	Promise used to return the requestResult object.

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, sendMessageRequest() of the proxy object is called to send a message.

let option = new rpc.MessageOption();
let data = rpc.MessageSequence.create();
let reply = rpc.MessageSequence.create();
data.writeInt(1);
data.writeString("hello");
proxy.sendMessageRequest(1, data, reply, option)
  .then((result: rpc.RequestResult) => {
    if (result.errCode === 0) {
      console.log("sendMessageRequest got result");
      result.reply.readException();
      let msg = result.reply.readString();
      console.log("RPCTest: reply msg: " + msg);
    } else {
      console.log("RPCTest: sendMessageRequest failed, errCode: " + result.errCode);
    }
  }).catch((e: Error) => {
    console.log("RPCTest: sendMessageRequest got exception: " + e.message);
  }).finally (() => {
    console.log("RPCTest: sendMessageRequest ends, reclaim parcel");
    data.reclaim();
    reply.reclaim();
  });

sendRequest^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use sendMessageRequest.

sendRequest(code: number, data: MessageParcel, reply: MessageParcel, options: MessageOption): Promise<SendRequestResult>

Sends a MessageParcel message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a promise will be fulfilled immediately and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a promise will be fulfilled when the response to sendRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageParcel	Yes	MessageParcel object holding the data to send.
reply	MessageParcel	Yes	MessageParcel object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.

Return value

Type	Description
Promise<SendRequestResult>	Promise used to return the sendRequestResult object.

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, sendMessageRequest() of the proxy object is called to send a message.

let option = new rpc.MessageOption();
let data = rpc.MessageParcel.create();
let reply = rpc.MessageParcel.create();
data.writeInt(1);
data.writeString("hello");
proxy.sendRequest(1, data, reply, option)
  .then((result: rpc.SendRequestResult) => {
    if (result.errCode === 0) {
      console.log("sendRequest got result");
      result.reply.readException();
      let msg = result.reply.readString();
      console.log("RPCTest: reply msg: " + msg);
    } else {
      console.log("RPCTest: sendRequest failed, errCode: " + result.errCode);
    }
  }).catch((e: Error) => {
    console.log("RPCTest: sendRequest got exception: " + e.message);
  }).finally (() => {
    console.log("RPCTest: sendRequest ends, reclaim parcel");
    data.reclaim();
    reply.reclaim();
  });

sendMessageRequest⁹⁺

sendMessageRequest(code: number, data: MessageSequence, reply: MessageSequence, options: MessageOption, callback: AsyncCallback<RequestResult>): void

Sends a MessageSequence message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a callback will be called immediately, and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a callback will be invoked at certain time after the response to sendMessageRequest is returned, and the reply contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageSequence	Yes	MessageSequence object holding the data to send.
reply	MessageSequence	Yes	MessageSequence object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.
callback	AsyncCallback<RequestResult>	Yes	Callback for receiving the sending result.

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';
import { BusinessError } from '@ohos.base'; 

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};
function sendRequestCallback(err: BusinessError, result: rpc.RequestResult) {
  if (result.errCode === 0) {
    console.log("sendRequest got result");
    result.reply.readException();
    let msg = result.reply.readString();
    console.log("RPCTest: reply msg: " + msg);
  } else {
    console.log("RPCTest: sendRequest failed, errCode: " + result.errCode);
  }
  console.log("RPCTest: sendRequest ends, reclaim parcel");
  result.data.reclaim();
  result.reply.reclaim();
}

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, sendMessageRequest() of the proxy object is called to send a message.

import { BusinessError } from '@ohos.base';

let option = new rpc.MessageOption();
let data = rpc.MessageSequence.create();
let reply = rpc.MessageSequence.create();
data.writeInt(1);
data.writeString("hello");
try {
  proxy.sendMessageRequest(1, data, reply, option, sendRequestCallback);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc send sequence request fail, errorCode " + e.code);
  console.info("rpc send sequence request fail, errorMessage " + e.message);
}

sendRequest^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use sendMessageRequest.

sendRequest(code: number, data: MessageParcel, reply: MessageParcel, options: MessageOption, callback: AsyncCallback<SendRequestResult>): void

Sends a MessageParcel message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a callback will be called immediately, and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a callback will be invoked when the response to sendRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageParcel	Yes	MessageParcel object holding the data to send.
reply	MessageParcel	Yes	MessageParcel object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.
callback	AsyncCallback<SendRequestResult>	Yes	Callback for receiving the sending result.

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';
import { BusinessError } from '@ohos.base';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
    bundleName: "com.ohos.server",
    abilityName: "com.ohos.server.EntryAbility",
};
function sendRequestCallback(err: BusinessError, result: rpc.SendRequestResult) {
  if (result.errCode === 0) {
    console.log("sendRequest got result");
    result.reply.readException();
    let msg = result.reply.readString();
    console.log("RPCTest: reply msg: " + msg);
  } else {
    console.log("RPCTest: sendRequest failed, errCode: " + result.errCode);
  }
  console.log("RPCTest: sendRequest ends, reclaim parcel");
  result.data.reclaim();
  result.reply.reclaim();
}

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect); 

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, sendMessageRequest() of the proxy object is called to send a message.

let option = new rpc.MessageOption();
let data = rpc.MessageParcel.create();
let reply = rpc.MessageParcel.create();
data.writeInt(1);
data.writeString("hello");
proxy.sendRequest(1, data, reply, option, sendRequestCallback);

getLocalInterface⁹⁺

getLocalInterface(interface: string): IRemoteBroker

Obtains the LocalInterface object of an interface token.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
interface	string	Yes	Interface descriptor.

Return value

Type	Description
IRemoteBroker	Returns Null by default, which indicates a proxy interface.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900006	only remote object permitted

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, getLocalInterface() of the proxy object is called to obtain the interface descriptor.

import { BusinessError } from '@ohos.base';

try {
  let broker: rpc.IRemoteBroker = proxy.getLocalInterface("testObject");
  console.log("RpcClient: getLocalInterface is " + broker);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc get local interface fail, errorCode " + e.code);
  console.info("rpc get local interface fail, errorMessage " + e.message);
}

queryLocalInterface^(deprecated)

This API is no longer maintained since API version 9. You are advised to use getLocalInterface.

queryLocalInterface(interface: string): IRemoteBroker

Obtains the LocalInterface object of an interface token.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
interface	string	Yes	Interface descriptor.

Return value

Type	Description
IRemoteBroker	Returns Null by default, which indicates a proxy interface.

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, queryLocalInterface() of the proxy object is called to obtain the interface descriptor.

let broker: rpc.IRemoteBroker  = proxy.queryLocalInterface("testObject");
console.log("RpcClient: queryLocalInterface is " + broker);

registerDeathRecipient⁹⁺

registerDeathRecipient(recipient: DeathRecipient, flags: number): void

Registers a callback for receiving death notifications of the remote object. The callback will be invoked when the remote object process matching the RemoteProxy object is killed.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
recipient	DeathRecipient	Yes	Callback to register.
flags	number	Yes	Flag of the death notification.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900008	proxy or remote object is invalid

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, registerDeathRecipient() of the proxy object is called to register a callback for receiving the death notification of the remote object.

import { BusinessError } from '@ohos.base';

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
let deathRecipient = new MyDeathRecipient();
try {
  proxy.registerDeathRecipient(deathRecipient, 0);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("proxy register deathRecipient fail, errorCode " + e.code);
  console.info("proxy register deathRecipient fail, errorMessage " + e.message);
}

addDeathRecipient^(deprecated)

This API is no longer maintained since API version 9. You are advised to use registerDeathRecipient.

addDeathRecipient(recipient: DeathRecipient, flags: number): boolean

Adds a callback for receiving the death notifications of the remote object, including the death notifications of the remote proxy.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
recipient	DeathRecipient	Yes	Callback to add.
flags	number	Yes	Flag of the death notification. This parameter is reserved. It is set to 0.

Return value

Type	Description
boolean	Returns true if the callback is added successfully; returns false otherwise.

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, addDeathRecipient() of the proxy object is called to add a callback for receiving the death notification of the remove object.

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
let deathRecipient = new MyDeathRecipient();
proxy.addDeathRecipient(deathRecipient, 0);

unregisterDeathRecipient⁹⁺

unregisterDeathRecipient(recipient: DeathRecipient, flags: number): void

Unregisters the callback used to receive death notifications of the remote object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
recipient	DeathRecipient	Yes	Callback to unregister.
flags	number	Yes	Flag of the death notification.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900008	proxy or remote object is invalid

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, unregisterDeathRecipient() of the proxy object is called to unregister the callback for receiving the death notification of the remote object.

import { BusinessError } from '@ohos.base';

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
let deathRecipient = new MyDeathRecipient();
try {
  proxy.registerDeathRecipient(deathRecipient, 0);
  proxy.unregisterDeathRecipient(deathRecipient, 0);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("proxy register deathRecipient fail, errorCode " + e.code);
  console.info("proxy register deathRecipient fail, errorMessage " + e.message);
}

removeDeathRecipient^(deprecated)

This API is no longer maintained since API version 9. You are advised to use unregisterDeathRecipient.

removeDeathRecipient(recipient: DeathRecipient, flags: number): boolean

Removes the callback used to receive death notifications of the remote object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
recipient	DeathRecipient	Yes	Callback to remove.
flags	number	Yes	Flag of the death notification. This parameter is reserved. It is set to 0.

Return value

Type	Description
boolean	Returns true if the callback is removed; returns false otherwise.

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, removeDeathRecipient() of the proxy object is called to remove the callback used to receive the death notification of the remote object.

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
let deathRecipient = new MyDeathRecipient();
proxy.addDeathRecipient(deathRecipient, 0);
proxy.removeDeathRecipient(deathRecipient, 0);

getDescriptor⁹⁺

getDescriptor(): string

Obtains the interface descriptor (which is a string) of this proxy object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	Interface descriptor obtained.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900008	proxy or remote object is invalid
1900007	communication failed

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, getDescriptor() of the proxy object is called to obtain the interface descriptor of the object.

import { BusinessError } from '@ohos.base';

try {
  let descriptor: string = proxy.getDescriptor();
  console.log("RpcClient: descriptor is " + descriptor);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc get interface descriptor fail, errorCode " + e.code);
  console.info("rpc get interface descriptor fail, errorMessage " + e.message);
}

getInterfaceDescriptor^(deprecated)

This API is no longer maintained since API version 9. You are advised to use getDescriptor.

getInterfaceDescriptor(): string

Obtains the interface descriptor of this proxy object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	Interface descriptor obtained.

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, getInterfaceDescriptor() of the proxy object is called to obtain the interface descriptor of the current proxy object.

let descriptor: string = proxy.getInterfaceDescriptor();
console.log("RpcClient: descriptor is " + descriptor);

isObjectDead

isObjectDead(): boolean

Checks whether the RemoteObject is dead.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
boolean	Returns true if the RemoteObject is dead; returns false otherwise.

Example

Before obtaining the ability for the application developed based on the stage model, obtain the context. For details, see Obtaining the Context.

// Import @ohos.ability.featureAbility only for the application developed based on the FA model.
// import FA from "@ohos.ability.featureAbility";
import Want from '@ohos.app.ability.Want';
import common from '@ohos.app.ability.common';

let proxy: rpc.IRemoteObject|undefined = undefined;
let connect: common.ConnectOptions = {
  onConnect: (elementName, remoteProxy) => {
    console.log("RpcClient: js onConnect called.");
    proxy = remoteProxy;
  },
  onDisconnect: (elementName) => {
    console.log("RpcClient: onDisconnect");
  },
  onFailed: () => {
    console.log("RpcClient: onFailed");
  }
};
let want: Want = {
  bundleName: "com.ohos.server",
  abilityName: "com.ohos.server.EntryAbility",
};

// Use this method to connect to the ability for the FA model.
// FA.connectAbility(want,connect);

this.context.connectServiceExtensionAbility(want, connect);

The proxy object in the onConnect callback can be assigned a value only after the ability is connected asynchronously. Then, isObjectDead() of the proxy object is called to check whether this object is dead.

let isDead: boolean = proxy.isObjectDead();
console.log("RpcClient: isObjectDead is " + isDead);

MessageOption

Provides common message options (flag and wait time). Use the specified flag to construct the MessageOption object.

System capability: SystemCapability.Communication.IPC.Core

Name	Value	Description
TF_SYNC	0 (0x00)	Synchronous call.
TF_ASYNC	1 (0x01)	Asynchronous call.
TF_ACCEPT_FDS	16 (0x10)	Indication to sendMessageRequest9+ for returning the file descriptor.
TF_WAIT_TIME	4 (0x4)	Default waiting time, in seconds.

constructor⁹⁺

constructor(async?: boolean);

A constructor used to create a MessageOption object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
async	boolean	No	Call flag, which can be synchronous or asynchronous. The default value is synchronous.

Example

class TestRemoteObject extends rpc.MessageOption {
  constructor(async: boolean) {
    super(async);
  }
}

constructor

constructor(syncFlags?: number, waitTime?: number)

A constructor used to create a MessageOption object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
syncFlags	number	No	Call flag, which can be synchronous or asynchronous. The default value is synchronous.
waitTime	number	No	Maximum wait time for an RPC call. The default value is TF_WAIT_TIME.

Example

class TestRemoteObject extends rpc.MessageOption {
  constructor(syncFlags?: number,waitTime?: number) {
    super(syncFlags,waitTime);
  }
}

isAsync⁹⁺

isAsync(): boolean;

Checks whether SendMessageRequest is called synchronously or asynchronously.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
boolean	Returns true if SendMessageRequest is called asynchronously; returns false if it is called synchronously.

Example

let option = new rpc.MessageOption();
option.isAsync();

setAsync⁹⁺

setAsync(async: boolean): void;

Sets whether SendMessageRequest is called synchronously or asynchronously.

System capability: SystemCapability.Communication.IPC.Core

Example

let option = new rpc.MessageOption();
option.setAsync(true);
console.log("Set synchronization flag");

getFlags

getFlags(): number

Obtains the call flag, which can be synchronous or asynchronous.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Call mode obtained.

Example

try {
  let option = new rpc.MessageOption();
  console.info("create object successfully.");
  let flog = option.getFlags();
  console.info("run getFlags success, flog is " + flog);
  option.setFlags(1)
  console.info("run setFlags success");
  let flog2 = option.getFlags();
  console.info("run getFlags success, flog2 is " + flog2);
} catch (error) {
  console.info("error " + error);
}

setFlags

setFlags(flags: number): void

Sets the call flag, which can be synchronous or asynchronous.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
flags	number	Yes	Call flag to set.

Example

try {
  let option = new rpc.MessageOption();
  option.setFlags(1)
  console.info("run setFlags success");
  let flog = option.getFlags();
  console.info("run getFlags success, flog is " + flog);
} catch (error) {
  console.info("error " + error);
}

getWaitTime

getWaitTime(): number

Obtains the maximum wait time for this RPC call.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Maximum wait time obtained.

Example

try {
  let option = new rpc.MessageOption();
  let time = option.getWaitTime();
  console.info("run getWaitTime success, time is " + time);
  option.setWaitTime(16);
  let time2 = option.getWaitTime();
  console.info("run getWaitTime success, time is " + time2);
} catch (error) {
  console.info("error " + error);
}

setWaitTime

setWaitTime(waitTime: number): void

Sets the maximum wait time for this RPC call.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
waitTime	number	Yes	Maximum wait time to set.

Example

try {
  let option = new rpc.MessageOption();
  option.setWaitTime(16);
  let time = option.getWaitTime();
  console.info("run getWaitTime success, time is " + time);
} catch (error) {
  console.info("error " + error);
}

IPCSkeleton

Obtains IPC context information, including the UID and PID, local and remote device IDs, and whether the method is invoked on the same device.

getContextObject

static getContextObject(): IRemoteObject

Obtains the system capability manager. This API is a static method.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
IRemoteObject	System capability manager obtained.

Example

let samgr = rpc.IPCSkeleton.getContextObject();
console.log("RpcServer: getContextObject result: " + samgr);

getCallingPid

static getCallingPid(): number

Obtains the PID of the caller. This API is a static method, which is invoked by the RemoteObject object in the onRemoteRequest method. If this method is not invoked in the IPC context (onRemoteRequest), the PID of the process will be returned.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	PID of the caller.

Example

class Stub extends rpc.RemoteObject {
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    let callerPid = rpc.IPCSkeleton.getCallingPid();
    console.log("RpcServer: getCallingPid result: " + callerPid);
    return true;
  }
}

getCallingUid

static getCallingUid(): number

Obtains the UID of the caller. This API is a static method, which is invoked by the RemoteObject object in the onRemoteRequest method. If this method is not invoked in the IPC context (onRemoteRequest), the UID of the process will be returned.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	UID of the caller.

Example

class Stub extends rpc.RemoteObject {
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    let callerUid = rpc.IPCSkeleton.getCallingUid();
    console.log("RpcServer: getCallingUid result: " + callerUid);
    return true;
  }
}

getCallingTokenId⁸⁺

static getCallingTokenId(): number;

Obtains the caller's token ID, which is used to verify the caller identity.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Token ID of the caller obtained.

Example

class Stub extends rpc.RemoteObject {
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    let callerTokenId = rpc.IPCSkeleton.getCallingTokenId();
    console.log("RpcServer: getCallingTokenId result: " + callerTokenId);
    return true;
  }
}

getCallingDeviceID

static getCallingDeviceID(): string

Obtains the ID of the device hosting the caller's process. This API is a static method.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	Device ID obtained.

Example

class Stub extends rpc.RemoteObject {
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    let callerDeviceID = rpc.IPCSkeleton.getCallingDeviceID();
    console.log("RpcServer: callerDeviceID is: " + callerDeviceID);
    return true;
  }
}

getLocalDeviceID

static getLocalDeviceID(): string

Obtains the local device ID. This API is a static method.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	Local device ID obtained.

Example

class Stub extends rpc.RemoteObject {
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    let localDeviceID = rpc.IPCSkeleton.getLocalDeviceID();
    console.log("RpcServer: localDeviceID is: " + localDeviceID);
    return true;
  }
}

isLocalCalling

static isLocalCalling(): boolean

Checks whether the remote process is a process of the local device. This API is a static method.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
boolean	Returns true if the local and remote processes are on the same device; returns false otherwise.

Example

class Stub extends rpc.RemoteObject {
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    let isLocalCalling = rpc.IPCSkeleton.isLocalCalling();
    console.log("RpcServer: isLocalCalling is: " + isLocalCalling);
    return true;
  }
}

flushCmdBuffer⁹⁺

static flushCmdBuffer(object: IRemoteObject): void

Flushes all suspended commands from the specified RemoteProxy to the corresponding RemoteObject. This API is a static method. It is recommended that this method be called before any time-sensitive operation is performed.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
object	IRemoteObject	Yes	RemoteProxy specified.

Example

import { BusinessError } from '@ohos.base';

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
}
let remoteObject = new TestRemoteObject("aaa");
try {
  rpc.IPCSkeleton.flushCmdBuffer(remoteObject);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("proxy set calling identity fail, errorCode " + e.code);
  console.info("proxy set calling identity fail, errorMessage " + e.message);
}

flushCommands^(deprecated)

This API is no longer maintained since API version 9. You are advised to use flushCmdBuffer.

static flushCommands(object: IRemoteObject): number

Flushes all suspended commands from the specified RemoteProxy to the corresponding RemoteObject. This API is a static method. It is recommended that this method be called before any time-sensitive operation is performed.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
object	IRemoteObject	Yes	RemoteProxy specified.

Return value

Type	Description
number	Returns 0 if the operation is successful; returns an error code if the input object is null or a RemoteObject, or if the operation fails.

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
}
let remoteObject = new TestRemoteObject("aaa");
let ret = rpc.IPCSkeleton.flushCommands(remoteObject);
console.log("RpcServer: flushCommands result: " + ret);

resetCallingIdentity

static resetCallingIdentity(): string

Changes the UID and PID of the remote user to the UID and PID of the local user. This API is a static method. You can use it in scenarios such as identity authentication.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	String containing the UID and PID of the remote user.

Example

class Stub extends rpc.RemoteObject {
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    let callingIdentity = rpc.IPCSkeleton.resetCallingIdentity();
    console.log("RpcServer: callingIdentity is: " + callingIdentity);
    return true;
  }
}

restoreCallingIdentity⁹⁺

static restoreCallingIdentity(identity: string): void

Changes the UID and PID of the remote user to the UID and PID of the local user. This API is a static method. You can use it in scenarios such as identity authentication.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
identity	string	Yes	String containing the remote user UID and PID, which are returned by resetCallingIdentity.

Example

class Stub extends rpc.RemoteObject {
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    let callingIdentity: rpc.IPCSkeleton|undefined = undefined;
    try {
      callingIdentity = rpc.IPCSkeleton.resetCallingIdentity();
      console.log("RpcServer: callingIdentity is: " + callingIdentity);
    } finally {
      rpc.IPCSkeleton.restoreCallingIdentity("callingIdentity ");
    }
    return true;
  }
}

setCallingIdentity^(deprecated)

This API is no longer maintained since API version 9. You are advised to use restoreCallingIdentity.

static setCallingIdentity(identity: string): boolean

Sets the UID and PID of the remote user. This API is a static method. It is usually called when the UID and PID of the remote user are required. The UID and PID of the remote user are returned by resetCallingIdentity.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
identity	string	Yes	String containing the remote user UID and PID, which are returned by resetCallingIdentity.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

class Stub extends rpc.RemoteObject {
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    let callingIdentity: rpc.IPCSkeleton|undefined = undefined;
    try {
      callingIdentity = rpc.IPCSkeleton.resetCallingIdentity();
      console.log("RpcServer: callingIdentity is: " + callingIdentity);
    } finally {
      let ret = rpc.IPCSkeleton.setCallingIdentity("callingIdentity ");
      console.log("RpcServer: setCallingIdentity is: " + ret);
    }
    return true;
  }
}

RemoteObject

Provides methods to implement RemoteObject. The service provider must inherit from this class.

constructor

constructor(descriptor: string)

A constructor used to create a RemoteObject object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
descriptor	string	Yes	Interface descriptor.

sendRequest^(deprecated)

This API is no longer maintained since API version 9. You are advised to use sendMessageRequest.

sendRequest(code: number, data: MessageParcel, reply: MessageParcel, options: MessageOption): boolean

Sends a MessageParcel message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a promise will be fulfilled immediately and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a promise will be fulfilled when the response to sendRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageParcel	Yes	MessageParcel object holding the data to send.
reply	MessageParcel	Yes	MessageParcel object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.

Return value

Type	Description
boolean	Returns true if the message is sent successfully; returns false otherwise.

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
}
let testRemoteObject = new TestRemoteObject("testObject");
let option = new rpc.MessageOption();
let data = rpc.MessageParcel.create();
let reply = rpc.MessageParcel.create();
data.writeInt(1);
data.writeString("hello");
let ret: boolean = testRemoteObject.sendRequest(1, data, reply, option);
if (ret) {
  console.log("sendRequest got result");
  let msg = reply.readString();
  console.log("RPCTest: reply msg: " + msg);
} else {
  console.log("RPCTest: sendRequest failed");
}
console.log("RPCTest: sendRequest ends, reclaim parcel");
data.reclaim();
reply.reclaim();

sendRequest^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use sendMessageRequest.

sendRequest(code: number, data: MessageParcel, reply: MessageParcel, options: MessageOption): Promise<SendRequestResult>

Sends a MessageParcel message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a promise will be fulfilled immediately and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a promise will be fulfilled when the response to sendRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageParcel	Yes	MessageParcel object holding the data to send.
reply	MessageParcel	Yes	MessageParcel object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.

Return value

Type	Description
Promise<SendRequestResult>	Promise used to return the sendRequestResult object.

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
}
let testRemoteObject = new TestRemoteObject("testObject");
let option = new rpc.MessageOption();
let data = rpc.MessageParcel.create();
let reply = rpc.MessageParcel.create();
data.writeInt(1);
data.writeString("hello");
let a = testRemoteObject.sendRequest(1, data, reply, option) as Object;
let b = a as Promise<rpc.SendRequestResult>;
b.then((result: rpc.SendRequestResult) => {
  if (result.errCode === 0) {
    console.log("sendRequest got result");
    result.reply.readException();
    let msg = result.reply.readString();
    console.log("RPCTest: reply msg: " + msg);
  } else {
    console.log("RPCTest: sendRequest failed, errCode: " + result.errCode);
  }
}).catch((e: Error) => {
  console.log("RPCTest: sendRequest got exception: " + e.message);
}).finally (() => {
  console.log("RPCTest: sendRequest ends, reclaim parcel");
  data.reclaim();
  reply.reclaim();
});

sendMessageRequest⁹⁺

sendMessageRequest(code: number, data: MessageSequence, reply: MessageSequence, options: MessageOption): Promise<RequestResult>

Sends a MessageSequence message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a promise will be fulfilled immediately and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a promise will be fulfilled when the response to sendMessageRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageSequence	Yes	MessageSequence object holding the data to send.
reply	MessageSequence	Yes	MessageSequence object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.

Return value

Type	Description
Promise<RequestResult>	Promise used to return the RequestResult instance.

Example

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
}
let testRemoteObject = new TestRemoteObject("testObject");
let option = new rpc.MessageOption();
let data = rpc.MessageSequence.create();
let reply = rpc.MessageSequence.create();
data.writeInt(1);
data.writeString("hello");
testRemoteObject.sendMessageRequest(1, data, reply, option)
  .then((result: rpc.RequestResult) => {
    if (result.errCode === 0) {
      console.log("sendMessageRequest got result");
      result.reply.readException();
      let msg = result.reply.readString();
      console.log("RPCTest: reply msg: " + msg);
    } else {
      console.log("RPCTest: sendMessageRequest failed, errCode: " + result.errCode);
    }
  }).catch((e: Error) => {
    console.log("RPCTest: sendMessageRequest got exception: " + e.message);
  }).finally (() => {
    console.log("RPCTest: sendMessageRequest ends, reclaim parcel");
    data.reclaim();
    reply.reclaim();
  });

sendMessageRequest⁹⁺

sendMessageRequest(code: number, data: MessageSequence, reply: MessageSequence, options: MessageOption, callback: AsyncCallback<RequestResult>): void

Sends a MessageSequence message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a callback will be called immediately, and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a callback will be invoked when the response to sendMessageRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageSequence	Yes	MessageSequence object holding the data to send.
reply	MessageSequence	Yes	MessageSequence object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.
AsyncCallback	AsyncCallback<RequestResult>	Yes	Callback for receiving the sending result.

Example

import { BusinessError } from '@ohos.base';

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
}
function sendRequestCallback(err: BusinessError, result: rpc.RequestResult) {
  if (result.errCode === 0) {
    console.log("sendRequest got result");
    result.reply.readException();
    let msg = result.reply.readString();
    console.log("RPCTest: reply msg: " + msg);
  } else {
    console.log("RPCTest: sendRequest failed, errCode: " + result.errCode);
  }
  console.log("RPCTest: sendRequest ends, reclaim parcel");
  result.data.reclaim();
  result.reply.reclaim();
}
let testRemoteObject = new TestRemoteObject("testObject");
let option = new rpc.MessageOption();
let data = rpc.MessageSequence.create();
let reply = rpc.MessageSequence.create();
data.writeInt(1);
data.writeString("hello");
testRemoteObject.sendMessageRequest(1, data, reply, option, sendRequestCallback);

sendRequest^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use sendMessageRequest.

sendRequest(code: number, data: MessageParcel, reply: MessageParcel, options: MessageOption, callback: AsyncCallback<SendRequestResult>): void

Sends a MessageParcel message to the remote process in synchronous or asynchronous mode. If asynchronous mode is set in options, a callback will be called immediately, and the reply message is empty. The specific reply needs to be obtained from the callback on the service side. If synchronous mode is set in options, a callback will be invoked when the response to sendRequest is returned, and the reply message contains the returned information.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Message code (1-16777215) called by the request, which is determined by the communication parties. If the method is generated by an IDL tool, the message code is automatically generated by the IDL tool.
data	MessageParcel	Yes	MessageParcel object holding the data to send.
reply	MessageParcel	Yes	MessageParcel object that receives the response.
options	MessageOption	Yes	Request sending mode, which can be synchronous (default) or asynchronous.
AsyncCallback	AsyncCallback<SendRequestResult>	Yes	Callback for receiving the sending result.

Example

import { BusinessError } from '@ohos.base';

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
}
function sendRequestCallback(err: BusinessError, result: rpc.SendRequestResult) {
  if (result.errCode === 0) {
    console.log("sendRequest got result");
    result.reply.readException();
    let msg = result.reply.readString();
    console.log("RPCTest: reply msg: " + msg);
  } else {
    console.log("RPCTest: sendRequest failed, errCode: " + result.errCode);
  }
  console.log("RPCTest: sendRequest ends, reclaim parcel");
  result.data.reclaim();
  result.reply.reclaim();
}
let testRemoteObject = new TestRemoteObject("testObject");
let option = new rpc.MessageOption();
let data = rpc.MessageParcel.create();
let reply = rpc.MessageParcel.create();
data.writeInt(1);
data.writeString("hello");
testRemoteObject.sendRequest(1, data, reply, option, sendRequestCallback);

onRemoteRequest^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use onRemoteMessageRequest.

onRemoteRequest(code: number, data: MessageParcel, reply: MessageParcel, options: MessageOption): boolean

Provides a response to sendMessageRequest(). The server processes the request and returns a response in this API.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Service request code sent by the remote end.
data	MessageParcel	Yes	MessageParcel object that holds the parameters called by the client.
reply	MessageParcel	Yes	MessageParcel object carrying the result.
option	MessageOption	Yes	Whether the operation is synchronous or asynchronous.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
  onRemoteRequest(code: number, data: rpc.MessageParcel, reply: rpc.MessageParcel, option: rpc.MessageOption): boolean {
    if (code === 1) {
      console.log("RpcServer: onRemoteRequest called");
      return true;
    } else {
      console.log("RpcServer: unknown code: " + code);
      return false;
    }
  }
}

onRemoteMessageRequest⁹⁺

onRemoteMessageRequest(code: number, data: MessageSequence, reply: MessageSequence, options: MessageOption): boolean|Promise<boolean>

NOTE

• You are advised to overload onRemoteMessageRequest preferentially, which implements synchronous and asynchronous message processing.
• If both onRemoteRequest() and onRemoteMessageRequest() are overloaded, only the onRemoteMessageRequest() takes effect.

Provides a response to sendMessageRequest(). The server processes the request synchronously or asynchronously and returns the result in this API.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
code	number	Yes	Service request code sent by the remote end.
data	MessageSequence	Yes	MessageSequence object that holds the parameters called by the client.
reply	MessageSequence	Yes	MessageSequence object to which the result is written.
option	MessageOption	Yes	Whether the operation is synchronous or asynchronous.

Return value

Type	Description
boolean	Returns a Boolean value if the request is processed synchronously in onRemoteMessageRequest. The value true means the operation is successful; the value false means the opposite.
Promise<boolean>	Returns a promise object if the request is processed asynchronously in onRemoteMessageRequest.

Example: Overload onRemoteMessageRequest to process requests synchronously.

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }

  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    if (code === 1) {
      console.log("RpcServer: sync onRemoteMessageRequest is called");
      return true;
    } else {
      console.log("RpcServer: unknown code: " + code);
      return false;
    }
  }
}

Example: Overload onRemoteMessageRequest to process requests asynchronously.

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }

  async onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): Promise<boolean> {
    if (code === 1) {
      console.log("RpcServer: async onRemoteMessageRequest is called");
    } else {
      console.log("RpcServer: unknown code: " + code);
      return false;
    }
    await new Promise((resolve: (data: rpc.RequestResult) => void) => {
      setTimeout(resolve, 100);
    })
    return true;
  }
}

Example: Overload onRemoteMessageRequest and onRemoteRequest to process requests synchronously.

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }

  onRemoteRequest(code: number, data: rpc.MessageParcel, reply: rpc.MessageParcel, option: rpc.MessageOption): boolean {
     if (code === 1) {
        console.log("RpcServer: sync onRemoteMessageRequest is called");
        return true;
     } else {
        console.log("RpcServer: unknown code: " + code);
        return false;
     }
  }
    // Only onRemoteMessageRequest is executed.
  onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): boolean|Promise<boolean> {
    if (code === 1) {
      console.log("RpcServer: async onRemoteMessageRequest is called");
    } else {
      console.log("RpcServer: unknown code: " + code);
      return false;
    }
    return true;
  }
}

Example: Overload onRemoteMessageRequest and onRemoteRequest to process requests asynchronously.

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }

  onRemoteRequest(code: number, data: rpc.MessageParcel, reply: rpc.MessageParcel, option: rpc.MessageOption): boolean {
    if (code === 1) {
      console.log("RpcServer: sync onRemoteRequest is called");
      return true;
    } else {
      console.log("RpcServer: unknown code: " + code);
      return false;
    }
  }
  // Only onRemoteMessageRequest is executed.
  async onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption): Promise<boolean> {
    if (code === 1) {
      console.log("RpcServer: async onRemoteMessageRequest is called");
    } else {
      console.log("RpcServer: unknown code: " + code);
      return false;
    }
    await new Promise((resolve: (data: rpc.RequestResult) => void) => {
      setTimeout(resolve, 100);
    })
    return true;
  }
}

getCallingUid

getCallingUid(): number

Obtains the UID of the remote process.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	UID of the remote process obtained.

Example

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
}
let testRemoteObject = new TestRemoteObject("testObject");
console.log("RpcServer: getCallingUid: " + testRemoteObject.getCallingUid());

getCallingPid

getCallingPid(): number

Obtains the PID of the remote process.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	PID of the remote process obtained.

Example

class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
}
let testRemoteObject = new TestRemoteObject("testObject");
console.log("RpcServer: getCallingPid: " + testRemoteObject.getCallingPid());

getLocalInterface⁹⁺

getLocalInterface(descriptor: string): IRemoteBroker

Obtains the interface descriptor.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
descriptor	string	Yes	Interface descriptor.

Return value

Type	Description
IRemoteBroker	IRemoteBroker object bound to the specified interface token.

Example

import { BusinessError } from '@ohos.base';

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
    this.modifyLocalInterface(this, descriptor);
  }
  registerDeathRecipient(recipient: MyDeathRecipient, flags: number) {
    // Implement the method logic based on service requirements.
  }
  unregisterDeathRecipient(recipient: MyDeathRecipient, flags: number) {
    // Implement the method logic based on service requirements.
  }
  isObjectDead(): boolean {
    return false;
  }
}
let testRemoteObject = new TestRemoteObject("testObject");
try {
  testRemoteObject.getLocalInterface("testObject");
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc get local interface fail, errorCode " + e.code);
  console.info("rpc get local interface fail, errorMessage " + e.message);
}

queryLocalInterface^(deprecated)

This API is no longer maintained since API version 9. You are advised to use getLocalInterface.

queryLocalInterface(descriptor: string): IRemoteBroker

Checks whether the remote object corresponding to the specified interface token exists.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
descriptor	string	Yes	Interface descriptor.

Return value

Type	Description
IRemoteBroker	Returns the remote object if a match is found; returns Null otherwise.

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
    this.attachLocalInterface(this, descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
}
let testRemoteObject = new TestRemoteObject("testObject");
testRemoteObject.queryLocalInterface("testObject");

getDescriptor⁹⁺

getDescriptor(): string

Obtains the interface descriptor of this object. The interface descriptor is a string.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	Interface descriptor obtained.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900008	proxy or remote object is invalid

Example

import { BusinessError } from '@ohos.base';

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
  registerDeathRecipient(recipient: MyDeathRecipient, flags: number) {
    // Implement the method logic based on service requirements.
  }
  unregisterDeathRecipient(recipient: MyDeathRecipient, flags: number) {
    // Implement the method logic based on service requirements.
  }
  isObjectDead(): boolean {
    return false;
  }
}
let testRemoteObject = new TestRemoteObject("testObject");
try {
  let descriptor = testRemoteObject.getDescriptor();
  console.log("RpcServer: descriptor is: " + descriptor);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("rpc get local interface fail, errorCode " + e.code);
  console.info("rpc get local interface fail, errorMessage " + e.message);
}

getInterfaceDescriptor^(deprecated)

This API is no longer maintained since API version 9. You are advised to use getDescriptor.

getInterfaceDescriptor(): string

Obtains the interface descriptor.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
string	Interface descriptor obtained.

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
}
let testRemoteObject = new TestRemoteObject("testObject");
let descriptor = testRemoteObject.getInterfaceDescriptor();
console.log("RpcServer: descriptor is: " + descriptor);

modifyLocalInterface⁹⁺

modifyLocalInterface(localInterface: IRemoteBroker, descriptor: string): void

Binds an interface descriptor to an IRemoteBroker object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
localInterface	IRemoteBroker	Yes	IRemoteBroker object.
descriptor	string	Yes	Interface descriptor.

Example

import { BusinessError } from '@ohos.base';

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
    try {
      this.modifyLocalInterface(this, descriptor);
    } catch(error) {
      let e: BusinessError = error as BusinessError;
      console.info(" rpc attach local interface fail, errorCode " + e.code);
      console.info(" rpc attach local interface fail, errorMessage " + e.message);
    }
  }
  registerDeathRecipient(recipient: MyDeathRecipient, flags: number) {
    // Implement the method logic based on service requirements.
  }
  unregisterDeathRecipient(recipient: MyDeathRecipient, flags: number) {
    // Implement the method logic based on service requirements.
  }
  isObjectDead(): boolean {
    return false;
  }
  asObject(): rpc.IRemoteObject {
    return this;
  }
}
let testRemoteObject = new TestRemoteObject("testObject");

attachLocalInterface^(deprecated)

This API is no longer maintained since API version 9. You are advised to use modifyLocalInterface.

attachLocalInterface(localInterface: IRemoteBroker, descriptor: string): void

Binds an interface descriptor to an IRemoteBroker object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
localInterface	IRemoteBroker	Yes	IRemoteBroker object.
descriptor	string	Yes	Interface descriptor.

Example

class MyDeathRecipient implements rpc.DeathRecipient {
  onRemoteDied() {
    console.log("server died");
  }
}
class TestRemoteObject extends rpc.RemoteObject {
  constructor(descriptor: string) {
    super(descriptor);
    this.attachLocalInterface(this, descriptor);
  }
  addDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  removeDeathRecipient(recipient: MyDeathRecipient, flags: number): boolean {
    return true;
  }
  isObjectDead(): boolean {
    return false;
  }
  asObject(): rpc.IRemoteObject {
    return this;
  }
}
let testRemoteObject = new TestRemoteObject("testObject");

Ashmem⁸⁺

Provides methods related to anonymous shared memory objects, including creating, closing, mapping, and unmapping an Ashmem object, reading data from and writing data to an Ashmem object, obtaining the Ashmem size, and setting Ashmem protection.

System capability: SystemCapability.Communication.IPC.Core

The table below describes the protection types of the mapped memory.

Name	Value	Description
PROT_EXEC	4	The mapped memory is executable.
PROT_NONE	0	The mapped memory is inaccessible.
PROT_READ	1	The mapped memory is readable.
PROT_WRITE	2	The mapped memory is writeable.

create⁹⁺

static create(name: string, size: number): Ashmem

Creates an Ashmem object with the specified name and size. This API is a static method.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
name	string	Yes	Name of the Ashmem object to create.
size	number	Yes	Size (in bytes) of the Ashmem object to create.

Return value

Type	Description
Ashmem	Returns the Ashmem object if it is created successfully; returns null otherwise.

Example

import { BusinessError } from '@ohos.base';

let ashmem: rpc.Ashmem|undefined = undefined;
try {
  ashmem = rpc.Ashmem.create("ashmem", 1024*1024);
  let size = ashmem.getAshmemSize();
  console.log("RpcTest: get ashemm by create : " + ashmem + " size is : " + size);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("Rpc creat ashmem fail, errorCode " + e.code);
  console.info("Rpc creat ashmem  fail, errorMessage " + e.message);
}

createAshmem^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use create.

static createAshmem(name: string, size: number): Ashmem

Creates an Ashmem object with the specified name and size. This API is a static method.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
name	string	Yes	Name of the Ashmem object to create.
size	number	Yes	Size (in bytes) of the Ashmem object to create.

Return value

Type	Description
Ashmem	Returns the Ashmem object if it is created successfully; returns null otherwise.

Example

let ashmem = rpc.Ashmem.createAshmem("ashmem", 1024*1024);
let size = ashmem.getAshmemSize();
console.log("RpcTest: get ashemm by createAshmem : " + ashmem + " size is : " + size);

create⁹⁺

static create(ashmem: Ashmem): Ashmem

Creates an Ashmem object by copying the file descriptor of an existing Ashmem object. The two Ashmem objects point to the same shared memory region.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
ashmem	Ashmem	Yes	Existing Ashmem object.

Return value

Type	Description
Ashmem	Ashmem object created.

Example

import { BusinessError } from '@ohos.base';

try {
  let ashmem = rpc.Ashmem.create("ashmem", 1024*1024);
  let ashmem2 = rpc.Ashmem.create(ashmem);
  let size = ashmem2.getAshmemSize();
  console.log("RpcTest: get ashemm by create : " + ashmem2 + " size is : " + size);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("Rpc creat ashmem from existing fail, errorCode " + e.code);
  console.info("Rpc creat ashmem from existing  fail, errorMessage " + e.message);
}

createAshmemFromExisting^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use create.

static createAshmemFromExisting(ashmem: Ashmem): Ashmem

Creates an Ashmem object by copying the file descriptor of an existing Ashmem object. The two Ashmem objects point to the same shared memory region.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
ashmem	Ashmem	Yes	Existing Ashmem object.

Return value

Type	Description
Ashmem	Ashmem object created.

Example

let ashmem = rpc.Ashmem.createAshmem("ashmem", 1024*1024);
let ashmem2 = rpc.Ashmem.createAshmemFromExisting(ashmem);
let size = ashmem2.getAshmemSize();
console.log("RpcTest: get ashemm by createAshmemFromExisting : " + ashmem2 + " size is : " + size);

closeAshmem⁸⁺

closeAshmem(): void

Closes this Ashmem object.

System capability: SystemCapability.Communication.IPC.Core

Example

let ashmem = rpc.Ashmem.create("ashmem", 1024*1024);
ashmem.closeAshmem();

unmapAshmem⁸⁺

unmapAshmem(): void

Deletes the mappings for the specified address range of this Ashmem object.

System capability: SystemCapability.Communication.IPC.Core

Example

let ashmem = rpc.Ashmem.create("ashmem", 1024*1024);
ashmem.unmapAshmem();

getAshmemSize⁸⁺

getAshmemSize(): number

Obtains the memory size of this Ashmem object.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
number	Ashmem size obtained.

Example

let ashmem = rpc.Ashmem.createAshmem("ashmem", 1024*1024);
let size = ashmem.getAshmemSize();
console.log("RpcTest: get ashmem is " + ashmem + " size is : " + size);

mapTypedAshmem⁹⁺

mapTypedAshmem(mapType: number): void

Creates the shared file mapping on the virtual address space of this process. The size of the mapping region is specified by this Ashmem object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
mapType	number	Yes	Protection level of the memory region to which the shared file is mapped.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900001	call mmap function failed

Example

import { BusinessError } from '@ohos.base';

let ashmem = rpc.Ashmem.create("ashmem", 1024*1024);
try {
  ashmem.mapTypedAshmem(ashmem.PROT_READ|ashmem.PROT_WRITE);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("Rpc map ashmem fail, errorCode " + e.code);
  console.info("Rpc map ashmem fail, errorMessage " + e.message);
}

mapAshmem^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use mapTypedAshmem.

mapAshmem(mapType: number): boolean

Creates the shared file mapping on the virtual address space of this process. The size of the mapping region is specified by this Ashmem object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
mapType	number	Yes	Protection level of the memory region to which the shared file is mapped.

Return value

Type	Description
boolean	Returns true if the mapping is created; returns false otherwise.

Example

let ashmem = rpc.Ashmem.createAshmem("ashmem", 1024*1024);
let mapReadAndWrite = ashmem.mapAshmem(ashmem.PROT_READ|ashmem.PROT_WRITE);
console.log("RpcTest: map ashmem result is  : " + mapReadAndWrite);

mapReadWriteAshmem⁹⁺

mapReadWriteAshmem(): void

Maps the shared file to the readable and writable virtual address space of the process.

System capability: SystemCapability.Communication.IPC.Core

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900001	call mmap function failed

Example

import { BusinessError } from '@ohos.base';

let ashmem = rpc.Ashmem.create("ashmem", 1024*1024);
try {
  ashmem.mapReadWriteAshmem();
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("Rpc map read and write ashmem fail, errorCode " + e.code);
  console.info("Rpc map read and write ashmem fail, errorMessage " + e.message);
}

mapReadAndWriteAshmem^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use mapReadWriteAshmem.

mapReadAndWriteAshmem(): boolean

Maps the shared file to the readable and writable virtual address space of the process.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
boolean	Returns true if the mapping is created; returns false otherwise.

Example

let ashmem = rpc.Ashmem.createAshmem("ashmem", 1024*1024);
let mapResult = ashmem.mapReadAndWriteAshmem();
console.log("RpcTest: map ashmem result is  : " + mapResult);

mapReadonlyAshmem⁹⁺

mapReadonlyAshmem(): void

Maps the shared file to the read-only virtual address space of the process.

System capability: SystemCapability.Communication.IPC.Core

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900001	call mmap function failed

Example

import { BusinessError } from '@ohos.base';

let ashmem = rpc.Ashmem.create("ashmem", 1024*1024);
try {
  ashmem.mapReadonlyAshmem();
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("Rpc map read and write ashmem fail, errorCode " + e.code);
  console.info("Rpc map read and write ashmem fail, errorMessage " + e.message);
}

mapReadOnlyAshmem^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use mapReadonlyAshmem.

mapReadOnlyAshmem(): boolean

Maps the shared file to the read-only virtual address space of the process.

System capability: SystemCapability.Communication.IPC.Core

Return value

Type	Description
boolean	Returns true if the mapping is created; returns false otherwise.

Example

let ashmem = rpc.Ashmem.createAshmem("ashmem", 1024*1024);
let mapResult = ashmem.mapReadOnlyAshmem();
console.log("RpcTest: Ashmem mapReadOnlyAshmem result is : " + mapResult);

setProtectionType⁹⁺

setProtectionType(protectionType: number): void

Sets the protection level of the memory region to which the shared file is mapped.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
protectionType	number	Yes	Protection type to set.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900002	call os ioctl function failed

Example

import { BusinessError } from '@ohos.base';

let ashmem = rpc.Ashmem.create("ashmem", 1024*1024);
try {
  ashmem.setProtection(ashmem.PROT_READ);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("Rpc set protection type fail, errorCode " + e.code);
  console.info("Rpc set protection type fail, errorMessage " + e.message);
}

setProtection^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use setProtectionType.

setProtection(protectionType: number): boolean

Sets the protection level of the memory region to which the shared file is mapped.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
protectionType	number	Yes	Protection type to set.

Return value

Type	Description
boolean	Returns true if the operation is successful; returns false otherwise.

Example

let ashmem = rpc.Ashmem.createAshmem("ashmem", 1024*1024);
let result = ashmem.setProtection(ashmem.PROT_READ);
console.log("RpcTest: Ashmem setProtection result is : " + result);

writeAshmem⁹⁺

writeAshmem(buf: number[], size: number, offset: number): void

Writes data to the shared file associated with this Ashmem object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
buf	number[]	Yes	Data to write.
size	number	Yes	Size of the data to write.
offset	number	Yes	Start position of the data to write in the memory region associated with this Ashmem object.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900003	write to ashmem failed

Example

import { BusinessError } from '@ohos.base';

let ashmem = rpc.Ashmem.create("ashmem", 1024*1024);
ashmem.mapReadWriteAshmem();
let ByteArrayVar = [1, 2, 3, 4, 5];
try {
  ashmem.writeAshmem(ByteArrayVar, 5, 0);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("Rpc write to ashmem fail, errorCode " + e.code);
  console.info("Rpc write to ashmem fail, errorMessage " + e.message);
}

writeToAshmem^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use writeAshmem.

writeToAshmem(buf: number[], size: number, offset: number): boolean

Writes data to the shared file associated with this Ashmem object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
buf	number[]	Yes	Data to write.
size	number	Yes	Size of the data to write.
offset	number	Yes	Start position of the data to write in the memory region associated with this Ashmem object.

Return value

Type	Description
boolean	Returns true if the data is written successfully; returns false otherwise.

Example

let ashmem = rpc.Ashmem.createAshmem("ashmem", 1024*1024);
let mapResult = ashmem.mapReadAndWriteAshmem();
console.info("RpcTest map ashmem result is " + mapResult);
let ByteArrayVar = [1, 2, 3, 4, 5];
let writeResult = ashmem.writeToAshmem(ByteArrayVar, 5, 0);
console.log("RpcTest: write to Ashmem result is  : " + writeResult);

readAshmem⁹⁺

readAshmem(size: number, offset: number): number[]

Reads data from the shared file associated with this Ashmem object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
size	number	Yes	Size of the data to read.
offset	number	Yes	Start position of the data to read in the memory region associated with this Ashmem object.

Return value

Type	Description
number[]	Data read.

Error codes

For details about the error codes, see RPC Error Codes.

ID	Error Message
1900004	read from ashmem failed

Example

import { BusinessError } from '@ohos.base';

let ashmem = rpc.Ashmem.create("ashmem", 1024*1024);
ashmem.mapReadWriteAshmem();
let ByteArrayVar = [1, 2, 3, 4, 5];
ashmem.writeAshmem(ByteArrayVar, 5, 0);
try {
  let readResult = ashmem.readAshmem(5, 0);
  console.log("RpcTest: read from Ashmem result is  : " + readResult);
} catch(error) {
  let e: BusinessError = error as BusinessError;
  console.info("Rpc read from ashmem fail, errorCode " + e.code);
  console.info("Rpc read from ashmem fail, errorMessage " + e.message);
}

readFromAshmem^{8+(deprecated)}

This API is no longer maintained since API version 9. You are advised to use readAshmem.

readFromAshmem(size: number, offset: number): number[]

Reads data from the shared file associated with this Ashmem object.

System capability: SystemCapability.Communication.IPC.Core

Parameters

Name	Type	Mandatory	Description
size	number	Yes	Size of the data to read.
offset	number	Yes	Start position of the data to read in the memory region associated with this Ashmem object.

Return value

Type	Description
number[]	Data read.

Example

 let ashmem = rpc.Ashmem.createAshmem("ashmem", 1024*1024);
 let mapResult = ashmem.mapReadAndWriteAshmem();
 console.info("RpcTest map ashmem result is " + mapResult);
 let ByteArrayVar = [1, 2, 3, 4, 5];
 let writeResult = ashmem.writeToAshmem(ByteArrayVar, 5, 0);
 console.log("RpcTest: write to Ashmem result is  : " + writeResult);
 let readResult = ashmem.readFromAshmem(5, 0);
 console.log("RpcTest: read to Ashmem result is  : " + readResult);

Obtaining the Context

Example This example describes only one method of obtaining the context. For details about more methods, see Obtaining the Context of UIAbility.

 import Ability from '@ohos.app.ability.UIAbility';
 import Want from '@ohos.app.ability.Want';
 import AbilityConstant from '@ohos.app.ability.AbilityConstant';
 import window from '@ohos.window';

 export default class MainAbility extends Ability {
   onCreate(want: Want, launchParam: AbilityConstant.LaunchParam) {
     console.log("[Demo] MainAbility onCreate");
     let context = this.context;
   }
   onDestroy() {
     console.log("[Demo] MainAbility onDestroy");
   }
   onWindowStageCreate(windowStage: window.WindowStage) {
     // Main window is created, set main page for this ability
     console.log("[Demo] MainAbility onWindowStageCreate");
   }
   onWindowStageDestroy() {
     // Main window is destroyed, release UI related resources
     console.log("[Demo] MainAbility onWindowStageDestroy");
   }
   onForeground() {
     // Ability has brought to foreground
     console.log("[Demo] MainAbility onForeground");
   }
   onBackground() {
     // Ability has back to background
     console.log("[Demo] MainAbility onBackground");
   }  
 };

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