Class (AVCastPickerHelper)

AVCastPickerHelper implements a semi-modal object used for casting. It displays a semi-modal window for users to select a target cast device. Before using the APIs of this class, you need to create an AVCastPickerHelper instance.

NOTE

• The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.
• The initial APIs of this class are supported since API version 14.
• The AVCastPickerHelper is displayed in semi-modal mode, and is actually bound to the full-modal page (bindContentCover).

Modules to Import

import { avSession } from '@kit.AVSessionKit';

constructor¹⁴⁺

constructor(context: Context)

Creates an AVCastPickerHelper instance. For details about how to obtain the context, see getHostContext.

Atomic service API: This API can be used in atomic services since API version 14.

System capability: SystemCapability.Multimedia.AVSession.AVCast

Parameters

Name	Type	Mandatory	Description
context	Context	Yes	Application context. (Only UIAbilityContext is supported.)

Error codes

For details about the error codes, see Universal Error Codes and AVSession Management Error Codes.

ID	Error Message
401	parameter check failed. 1.Mandatory parameters are left unspecified. 2.Incorrect parameter types.
6600101	Session service exception.

Example

import { avSession } from '@kit.AVSessionKit';

@Entry
@Component
struct Index {
  @State message: string = 'hello world';

  build() {
    Row() {
      Column() {
        Text(this.message)
          .fontSize(40)
          .fontWeight(FontWeight.Bold)
          .onClick(() => {
            let context = this.getUIContext().getHostContext() as Context;
            let avCastPicker = new avSession.AVCastPickerHelper(context);
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}

select¹⁴⁺

select(options?: AVCastPickerOptions): Promise<void>

Starts the AVCastPicker dialog box, where users can select the target cast device. This API uses a promise to return the result. You can pass in AVCastPickerOptions to specify the properties for selection.

Atomic service API: This API can be used in atomic services since API version 14.

System capability: SystemCapability.Multimedia.AVSession.AVCast

Parameters

Name	Type	Mandatory	Description
options	AVCastPickerOptions	No	AVCastPicker selection options. If this parameter is not specified, the default value of AVCastPickerOptions is used.

Return value

Type	Description
Promise<void>	Promise used to return the result. If the command is sent, no value is returned; otherwise, an error object is returned.

Error codes

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

ID	Error Message
401	parameter check failed. 1.Mandatory parameters are left unspecified. 2.Incorrect parameter types.

Example

import { common } from '@kit.AbilityKit';
import { avSession } from '@kit.AVSessionKit';

class MyPage {
  private avCastPicker: avSession.AVCastPickerHelper;

  constructor(context: common.Context) {
    this.avCastPicker = new avSession.AVCastPickerHelper(context);
  }

  async selectCastDevice() {
    const avCastPickerOptions: avSession.AVCastPickerOptions = {
      sessionType: 'video',
    };

this.avCastPicker.select(avCastPickerOptions).then(() => {
  console.info('Succeeded in selecting.');
});
  }
}

resetCommunicationDevice²¹⁺

resetCommunicationDevice(): Promise<void>

Restores the communication device of an application to the default device. For example, during a voice call, the communication device of the mobile phone is restored to the earpiece. This API uses a promise to return the result.

Atomic service API: This API can be used in atomic services since API version 21.

System capability: SystemCapability.Multimedia.AVSession.AVCast

Return value

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

Example

import { common } from '@kit.AbilityKit';
import { avSession } from '@kit.AVSessionKit';

async function avCastPicker(context: common.Context) {
  let avCastPicker = new avSession.AVCastPickerHelper(context);
  avCastPicker.resetCommunicationDevice().then(() => {
    console.info('Succeeded in resetting communication device.');
  });
}

on('pickerStateChange')¹⁴⁺

on(type: 'pickerStateChange', callback: Callback<AVCastPickerState>) : void

Subscribes to semi-modal window change events.

Multiple callbacks can be registered for this event. To ensure only the latest callback executes, unregister previous listeners first. Otherwise, all registered callbacks will fire on state changes.

Atomic service API: This API can be used in atomic services since API version 14.

System capability: SystemCapability.Multimedia.AVSession.AVCast

Parameters

Name	Type	Mandatory	Description
type	string	Yes	Event type. The event 'pickerStateChange' is triggered when the semi-modal window changes.
callback	Callback<AVCastPickerState>	Yes	Callback function, where the state parameter indicates the new state of the semi-modal window.

Error codes

For details about the error codes, see Universal Error Codes and AVSession Management Error Codes.

ID	Error Message
401	parameter check failed. 1.Mandatory parameters are left unspecified. 2.Incorrect parameter types.
6600101	Session service exception.

Example

import { common } from '@kit.AbilityKit';
import { AVCastPickerState } from '@kit.AVSessionKit';
import { avSession } from '@kit.AVSessionKit';

async function onPickerStateChange(context: common.Context) {
  let avCastPicker = new avSession.AVCastPickerHelper(context);
  avCastPicker.on('pickerStateChange', (state: AVCastPickerState) => {
    console.info(`picker state change : ${state}`);
  });
}

off('pickerStateChange')¹⁴⁺

off(type: 'pickerStateChange', callback?: Callback<AVCastPickerState>) : void

Unsubscribes from semi-modal window change events. If a callback is specified, the corresponding listener is unregistered. If no callback is specified, all listeners for the specified event are unregistered.

Atomic service API: This API can be used in atomic services since API version 14.

System capability: SystemCapability.Multimedia.AVSession.AVCast

Parameters

Name	Type	Mandatory	Description
type	string	Yes	Event type, which is 'pickerStateChange' in this case.
callback	Callback<AVCastPickerState>	No	Callback function, where the state parameter indicates the new state of the semi-modal window. If the unsubscription is successful, err is undefined; otherwise, err is an error object. The callback parameter is optional. If it is not specified, all the subscriptions to the specified event are canceled for this session.

Error codes

For details about the error codes, see Universal Error Codes and AVSession Management Error Codes.

ID	Error Message
401	parameter check failed. 1.Mandatory parameters are left unspecified. 2.Incorrect parameter types.
6600101	Session service exception.

Example

import { common } from '@kit.AbilityKit';
import { avSession } from '@kit.AVSessionKit';

async function onPickerStateChange(context: common.Context) {
  let avCastPicker = new avSession.AVCastPickerHelper(context);
  avCastPicker.off('pickerStateChange');
}