@ohos.nfc.controller (Standard NFC)

The nfcController module provides APIs for opening and closing Near-Field Communication (NFC) and reading the NFC state.

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.

Modules to Import

import { nfcController } from '@kit.ConnectivityKit';

NfcState

Enumerates the NFC states.

System capability: SystemCapability.Communication.NFC.Core

Atomic service API: This API can be used in atomic services since API version 12.

Name	Value	Description
STATE_OFF	1	NFC is closed (OFF).
STATE_TURNING_ON	2	NFC is turning on.
STATE_ON	3	NFC is open (ON).
STATE_TURNING_OFF	4	NFC is turning off.

nfcController.isNfcAvailable^(deprecated)

isNfcAvailable(): boolean

Checks whether the device supports NFC.

NOTE This API is supported since API version 7 and deprecated since API version 9. Use canIUse("SystemCapability.Communication.NFC.Core") instead.

System capability: SystemCapability.Communication.NFC.Core

Return value

Type	Description
boolean	Returns true if the device supports NFC; returns false otherwise.

nfcController.openNfc^(deprecated)

openNfc(): boolean

Opens NFC.

NOTE This API is supported since API version 7 and deprecated since API version 9. Use enableNfc instead.

Required permissions: ohos.permission.MANAGE_SECURE_SETTINGS (available only for system applications)

System capability: SystemCapability.Communication.NFC.Core

Return value

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

nfcController.enableNfc⁹⁺

enableNfc(): void

Enables NFC. This API can be called only by system applications.

Required permissions: ohos.permission.MANAGE_SECURE_SETTINGS (available only for system applications)

System capability: SystemCapability.Communication.NFC.Core

Error codes

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

ID	Error Message
201	Permission denied.
801	Capability not supported.
3100101	The NFC state is abnormal in the service.

nfcController.closeNfc^(deprecated)

closeNfc(): boolean

Closes NFC.

NOTE This API is supported since API version 7 and deprecated since API version 9. Use disableNfc instead.

Required permissions: ohos.permission.MANAGE_SECURE_SETTINGS (available only for system applications)

System capability: SystemCapability.Communication.NFC.Core

Return value

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

nfcController.disableNfc⁹⁺

disableNfc(): void

Disables NFC. This API can be called only by system applications.

Required permissions: ohos.permission.MANAGE_SECURE_SETTINGS (available only for system applications)

System capability: SystemCapability.Communication.NFC.Core

Error codes

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

ID	Error Message
201	Permission denied.
801	Capability not supported.
3100101	The NFC state is abnormal in the service.

nfcController.isNfcOpen

isNfcOpen(): boolean

Checks whether NFC is open.

System capability: SystemCapability.Communication.NFC.Core

Atomic service API: This API can be used in atomic services since API version 12.

Return value

Type	Description
boolean	Returns true if NFC is open; returns false otherwise.

nfcController.getNfcState

getNfcState(): NfcState

Obtains the NFC state.

System capability: SystemCapability.Communication.NFC.Core

Atomic service API: This API can be used in atomic services since API version 12.

Return value

Type	Description
NfcState	NFC state obtained. For details, see NfcState.

nfcController.on('nfcStateChange')

on(type: 'nfcStateChange', callback: Callback<NfcState>): void

Subscribes to NFC state changes. A callback will be invoked to return the NFC state when the NFC state changes.

System capability: SystemCapability.Communication.NFC.Core

Atomic service API: This API can be used in atomic services since API version 12.

Parameters

Name	Type	Mandatory	Description
type	string	Yes	Event type. The value is nfcStateChange.
callback	Callback<NfcState>	Yes	Callback used to return the NFC state.

nfcController.off('nfcStateChange')

off(type: 'nfcStateChange', callback?: Callback<NfcState>): void

Unsubscribes from the NFC state changes. The subscriber will not receive NFC state change notifications.

System capability: SystemCapability.Communication.NFC.Core

Atomic service API: This API can be used in atomic services since API version 12.

Parameters

Name	Type	Mandatory	Description
type	string	Yes	Event type. The value is nfcStateChange.
callback	Callback<NfcState>	No	Callback for the NFC state changes. This parameter can be left blank. If this parameter is not specified, this API unregisters all callbacks for the specified event.

Example

import { nfcController } from '@kit.ConnectivityKit';

// Register a callback for NFC status change events.
nfcController.on("nfcStateChange", (nfcState : number)=> {
  console.log("nfcController on callback nfcState: " + nfcState);
});

// Declare the ohos.permission.MANAGE_SECURE_SETTINGS permission for enabling NFC. This permission is available only for system applications.
if (!nfcController.isNfcOpen()) {
  // Use enableNfc to enable NFC since API version 9.
  try {
    nfcController.enableNfc();
    console.log("nfcController enableNfc success");
  } catch (businessError) {
    console.error("nfcController enableNfc businessError: " + businessError);
  }
} else {
  console.log("nfcController NFC has been opened");
}

// Declare the ohos.permission.MANAGE_SECURE_SETTINGS permission for disabling NFC. This permission is available only for system applications.
if (nfcController.isNfcOpen()) {
  // Use disableNfc to disable NFC since API version 9.
  try {
    nfcController.disableNfc();
    console.log("nfcController disableNfc success");
  } catch (businessError) {
    console.error("nfcController disableNfc businessError: " + businessError);
  }
} else {
  console.log("nfcController NFC has been closed");
}

// Unregister the callback for NFC status change events.
nfcController.off("nfcStateChange");