@ohos.scan (Scan) (System API)

This module provides JavaScript APIs of the scan framework for discovering and connecting to scanners.

NOTE The initial APIs of this module are supported since API version 20. This topic describes only system APIs provided by the module. For details about its public APIs, see @ohos.scan (Scan).

Modules to Import

import { scan } from '@kit.BasicServicesKit';

scan.addScanner

addScanner(uniqueId: string, discoveryMode: ScannerDiscoveryMode): Promise<void>

Adds a scanner. This API uses a promise to return the result.

Required permissions: ohos.permission.MANAGE_PRINT_JOB

System API: This is a system API.

System capability: SystemCapability.Print.PrintFramework

Parameters

Name	Type	Mandatory	Description
uniqueId	string	Yes	Unique ID of the scanner.
discoveryMode	ScannerDiscoveryMode	Yes	Discovery mode.

Return value

Type	Description
Promise<void>	Promise that returns no value.

Error codes

ID	Error Message
201	Permission denied.
202	Not system application.

Example

import { scan } from '@kit.BasicServicesKit';
import { BusinessError } from '@kit.BasicServicesKit';

let uniqueId: string = 'unique_scanner_001';
let discoveryMode: scan.ScannerDiscoveryMode = scan.ScannerDiscoveryMode.TCP_STR;
scan.addScanner(uniqueId, discoveryMode).then(() => {
    console.info('add scanner success');
}).catch((error: BusinessError) => {
    console.error('add scanner failed: ' + JSON.stringify(error));
})

scan.deleteScanner

deleteScanner(uniqueId: string, discoveryMode: ScannerDiscoveryMode): Promise<void>

Deletes a scanner. This API uses a promise to return the result.

Required permissions: ohos.permission.MANAGE_PRINT_JOB

System API: This is a system API.

System capability: SystemCapability.Print.PrintFramework

Parameters

Name	Type	Mandatory	Description
uniqueId	string	Yes	Unique ID of the scanner.
discoveryMode	ScannerDiscoveryMode	Yes	Discovery mode.

Return value

Type	Description
Promise<void>	Promise that returns no value.

Error codes

ID	Error Message
201	Permission denied.
202	Not system application.

Example

import { scan } from '@kit.BasicServicesKit';
import { BusinessError } from '@kit.BasicServicesKit';

let uniqueId: string = 'unique_scanner_001';
let discoveryMode: scan.ScannerDiscoveryMode = scan.ScannerDiscoveryMode.TCP_STR;
scan.deleteScanner(uniqueId, discoveryMode).then(() => {
    console.info('delete scanner success');
}).catch((error: BusinessError) => {
    console.error('delete scanner failed: ' + JSON.stringify(error));
})

scan.getAddedScanners

getAddedScanners(): Promise<ScannerDevice[]>

Obtains the added scanners. This API uses a promise to return the result.

Required permissions: ohos.permission.MANAGE_PRINT_JOB

System API: This is a system API.

System capability: SystemCapability.Print.PrintFramework

Return value

Type	Description
Promise<ScannerDevice[]>	Promise used to return the array of added scanners.

Error codes

ID	Error Message
201	Permission denied.
202	Not system application.

Example

import { scan } from '@kit.BasicServicesKit';
import { BusinessError } from '@kit.BasicServicesKit';

scan.getAddedScanners().then((scanners: scan.ScannerDevice[]) => {
    console.info('get added scanners success: ' + JSON.stringify(scanners));
}).catch((error: BusinessError) => {
    console.error('get added scanners failed: ' + JSON.stringify(error));
})

scan.on

on(type: 'scanDeviceAdd', callback: Callback<ScannerDevice>): void

Registers a callback used to listen for the scanner addition event. This API uses an asynchronous callback to return the result.

Required permissions: ohos.permission.MANAGE_PRINT_JOB

System API: This is a system API.

System capability: SystemCapability.Print.PrintFramework

Parameters

Name	Type	Mandatory	Description
type	'scanDeviceAdd'	Yes	Event type.
callback	Callback<ScannerDevice>	Yes	Callback used to return the added scanner.

Error codes

ID	Error Message
201	Permission denied.
202	Not system application.

Example

import { scan } from '@kit.BasicServicesKit';

scan.on('scanDeviceAdd', (device: scan.ScannerDevice) => {
    console.info('scan device add: ' + JSON.stringify(device));
})

scan.off

off(type: 'scanDeviceAdd', callback?: Callback<ScannerDevice>): void

Unregisters the callback used to listen for the scanner addition event. This API uses an asynchronous callback to return the result.

Required permissions: ohos.permission.MANAGE_PRINT_JOB

System API: This is a system API.

System capability: SystemCapability.Print.PrintFramework

Parameters

Name	Type	Mandatory	Description
type	'scanDeviceAdd'	Yes	Event type.
callback	Callback<ScannerDevice>	Yes	Callback used to return the added scanner.

Error codes

ID	Error Message
201	Permission denied.
202	Not system application.

Example

import { scan } from '@kit.BasicServicesKit';

let callback = (device: scan.ScannerDevice) => {
    console.info('scan device add: ' + JSON.stringify(device));
};
scan.on('scanDeviceAdd', callback);
// Unregister the callback.
scan.off('scanDeviceAdd', callback);

scan.on

on(type: 'scanDeviceDel', callback: Callback<ScannerDevice>): void

Registers a callback used to listen for the scanner deletion event. This API uses an asynchronous callback to return the result.

Required permissions: ohos.permission.MANAGE_PRINT_JOB

System API: This is a system API.

System capability: SystemCapability.Print.PrintFramework

Name	Type	Mandatory	Description
type	'scanDeviceDel'	Yes	Event type.
callback	Callback<ScannerDevice>	Yes	Callback used to return the deleted scanner.

Error codes

ID	Error Message
201	Permission denied.
202	Not system application.

Example

import { scan } from '@kit.BasicServicesKit';

scan.on('scanDeviceDel', (device: scan.ScannerDevice) => {
    console.info('scan device delete: ' + JSON.stringify(device));
})

scan.off

off(type: 'scanDeviceDel', callback?: Callback<ScannerDevice>): void

Unregisters the callback used to listen for the scanner deletion event. This API uses an asynchronous callback to return the result.

Required permissions: ohos.permission.MANAGE_PRINT_JOB

System API: This is a system API.

System capability: SystemCapability.Print.PrintFramework

Parameters

Name	Type	Mandatory	Description
type	'scanDeviceDel'	Yes	Event type.
callback	Callback<ScannerDevice>	No	Callback used to return the deleted scanner.

Error codes

ID	Error Message
201	Permission denied.
202	Not system application.

Example

import { scan } from '@kit.BasicServicesKit';

let callback = (device: scan.ScannerDevice) => {
    console.info('scan device delete: ' + JSON.stringify(device));
};
scan.on('scanDeviceDel', callback);
// Unregister the callback.
scan.off('scanDeviceDel', callback);