音频发声设备的切换与查询

class Options { 
  offset: number = 0; 
  length: number = 0; 
} 
 
@Entry 
@Component 
struct PreferOutputDevice { 
  private appContext?: common.Context; 
  private audioRendererOption: audio.AudioRendererOptions = { 
    streamInfo: { 
      samplingRate: audio.AudioSamplingRate.SAMPLE_RATE_44100, 
      channels: audio.AudioChannel.CHANNEL_2, 
      sampleFormat: audio.AudioSampleFormat.SAMPLE_FORMAT_S16LE, 
      encodingType: audio.AudioEncodingType.ENCODING_TYPE_RAW 
    }, 
    rendererInfo: { 
      content: audio.ContentType.CONTENT_TYPE_SPEECH, 
      usage: audio.StreamUsage.STREAM_USAGE_VOICE_COMMUNICATION, 
      rendererFlags: 0 
    } 
  }; 
  private audioRenderer?: audio.AudioRenderer; 
  private audioSource = 'test1.wav'; 
  private fileDescriptor?: resourceManager.RawFileDescriptor; 
  private audioRoutingManager?: audio.AudioRoutingManager; 
  @State preferOutputDeviceName: string = ''; 
 
  async aboutToAppear(): Promise<void> { 
    this.init(); 
  } 
 
  async init(): Promise<void> { 
    if (this.appContext) { 
      return; 
    } 
    this.appContext = getContext(); 
    let audioManager = audio.getAudioManager(); 
    this.audioRoutingManager = audioManager.getRoutingManager(); 
    this.audioRoutingManager.on('deviceChange', audio.DeviceFlag.OUTPUT_DEVICES_FLAG, async (deviceChanged) => { 
      await this.getPreferOutputDeviceForRendererInfo(); 
    }); 
    await this.getPreferOutputDeviceForRendererInfo(); 
    await this.getStageFileDescriptor(this.audioSource).then((res) => { 
      this.fileDescriptor = res; 
    }); 
    await this.renderPlay(); 
  } 
 
  async over(): Promise<void> { 
    this.appContext = undefined; 
    if (this.audioRenderer) { 
      await this.audioRenderer.release(); 
      this.audioRenderer = undefined; 
    } 
    if (this.fileDescriptor) { 
      this.closeResource(this.audioSource); 
      this.fileDescriptor = undefined; 
    } 
    this.audioRoutingManager = undefined; 
  } 
 
  onBackPress(): void { 
    this.over(); 
  } 
 
  async onPageHide(): Promise<void> { 
    this.over(); 
  } 
 
  onPageShow(): void { 
    this.init(); 
  } 
 
  async getStageFileDescriptor(fileName: string): Promise<resourceManager.RawFileDescriptor | undefined> { 
    let fileDescriptor: resourceManager.RawFileDescriptor | undefined = undefined; 
    if (this.appContext) { 
      let mgr = this.appContext.resourceManager; 
      await mgr.getRawFd(fileName).then(value => { 
        fileDescriptor = value; 
        console.log('case getRawFileDescriptor success fileName: ' + fileName); 
      }).catch((error: BusinessError) => { 
        console.log('case getRawFileDescriptor err: ' + error); 
      }); 
    } 
    return fileDescriptor; 
  } 
 
  async closeResource(fileName: string): Promise<void> { 
    if (this.appContext) { 
      let mgr = this.appContext.resourceManager; 
      await mgr.closeRawFd(fileName).then(() => { 
        console.log('case closeRawFd success fileName: ' + fileName); 
      }).catch((error: BusinessError) => { 
        console.log('case closeRawFd err: ' + error); 
      }); 
    } 
  } 
 
  getPreferOutputDeviceForRendererInfo(): void { 
    if (this.audioRoutingManager) { 
      this.audioRoutingManager.getPreferOutputDeviceForRendererInfo(this.audioRendererOption.rendererInfo) 
        .then(data => { 
          console.log(`getPreferOutputDeviceForRendererInfo data:${JSON.stringify(data[0])}`); 
          this.preferOutputDeviceName = this.getDeviceList(data[0]); 
        }).catch((err: BusinessError) => { 
        this.preferOutputDeviceName = 'Invalid'; 
        console.log(`getPreferOutputDeviceForRendererInfo err:${JSON.stringify(err)}`); 
      }); 
    } 
  } 
 
  getZNDeviceTypeName(deviceTypeName: string): string { 
    if (this.appContext) { 
      let map = new Map<string, string>(); 
      map.set('EARPIECE', this.appContext.resourceManager.getStringSync($r('app.string.EarPiece').id)); 
      map.set('SPEAKER', this.appContext.resourceManager.getStringSync($r('app.string.Speaker').id)); 
      map.set('WIRED_HEADSET', this.appContext.resourceManager.getStringSync($r('app.string.WiredHeadset').id)); 
      map.set('WIRED_HEADPHONES', this.appContext.resourceManager.getStringSync($r('app.string.WiredHeadPhones').id)); 
      map.set('BLUETOOTH_A2DP', this.appContext.resourceManager.getStringSync($r('app.string.Bluetooth_A2DP').id)); 
      map.set('BLUETOOTH_SCO', this.appContext.resourceManager.getStringSync($r('app.string.BLUETOOTH_SCO').id)); 
      map.set('USB_HEADSET', this.appContext.resourceManager.getStringSync($r('app.string.USB_Headset').id)); 
      if (map.get(deviceTypeName)) { 
        return map.get(deviceTypeName) as string; 
      } else { 
        return 'Invalid'; 
      } 
    } else { 
      return ''; 
    } 
  } 
 
  getDeviceList(deviceDescriptor: audio.AudioDeviceDescriptor): string { 
    let deviceTypeName = this.getDeviceTypeNameByValue(deviceDescriptor.deviceType); 
    return this.getZNDeviceTypeName(deviceTypeName); 
  } 
 
  getDeviceTypeNameByValue(value: audio.DeviceType): string { 
    let map = new Map<number, string>(); 
    map.set(1, 'EARPIECE'); 
    map.set(2, 'SPEAKER'); 
    map.set(3, 'WIRED_HEADSET'); 
    map.set(4, 'WIRED_HEADPHONES'); 
    map.set(8, 'BLUETOOTH_A2DP'); 
    map.set(7, 'BLUETOOTH_SCO'); 
    map.set(22, 'USB_HEADSET'); 
    if (map.get(value)) { 
      return map.get(value) as string; 
    } 
    return 'Invalid'; 
  } 
 
  async renderPlay(): Promise<void> { 
    if (this.audioRenderer) { 
      return; 
    } 
    try { 
      this.audioRenderer = await audio.createAudioRenderer(this.audioRendererOption); 
    } catch (err) { 
      let error = err as BusinessError; 
      console.error(`audioRenderer create : Error: ${JSON.stringify(error)}`); 
      return; 
    } 
    let bufferSize : number; 
    try { 
      bufferSize = await this.audioRenderer.getBufferSize(); 
      await this.audioRenderer.start(); 
    } catch (err) { 
      let error = err as BusinessError; 
      console.error(`audioRenderer start : Error: ${JSON.stringify(error)}`); 
      return; 
    } 
 
    try { 
      if (!this.fileDescriptor) { 
        return; 
      } 
      let startOffset = this.fileDescriptor.offset; 
      let cur = startOffset; 
      let buf = new ArrayBuffer(bufferSize); 
      while (true) { 
        // when render released,state is changed to STATE_RELEASED 
        if (this.audioRenderer.state === audio.AudioState.STATE_RELEASED) { 
          break; 
        } 
        while (cur <= startOffset + this.fileDescriptor.length) { 
          // when render released,state is changed to STATE_RELEASED 
          if (this.audioRenderer.state.valueOf() === audio.AudioState.STATE_RELEASED.valueOf()) { 
            break; 
          } 
          let options: Options = { 
            offset: cur, 
            length: bufferSize 
          } 
          await fs.read(this.fileDescriptor.fd, buf, options); 
          await this.audioRenderer.write(buf); 
          cur += bufferSize; 
        } 
        cur = startOffset; 
      } 
    } catch (err) { 
      let error = err as BusinessError; 
      console.error(`audioRenderer write : Error: ${JSON.stringify(error)}`); 
    } 
  } 
 
  build() { 
    Column() { 
      Row() { 
        Navigation() { 
          NavRouter() { 
            NavDestination() { 
            } 
          } 
        } 
        .height('100%') 
        .width('100%') 
        .hideBackButton(false) 
        .titleMode(NavigationTitleMode.Mini) 
        .title($r('app.string.SelectOutputDevice')) 
        .mode(NavigationMode.Stack); 
      }.height(56).width('100%').id('back_btn') 
      .onClick(async () => { 
        await router.pushUrl({ url: 'pages/Index' }); 
      }); 
 
      Column() { 
        Row() { 
          Row() { 
            Image($r('app.media.ic_call')).width(48).height(48); 
            Text($r('app.string.VoiceCallType')) 
              .fontSize(16) 
              .margin({ left: 12 }) 
              .fontFamily($r('sys.string.ohos_id_text_font_family_medium')) 
              .fontColor('#182431') 
              .fontWeight(500); 
          } 
 
          Row() { 
            Text(this.preferOutputDeviceName) 
              .id('device_name_text') 
              .fontFamily($r('sys.string.ohos_id_text_font_family_medium')) 
              .fontColor('#182431') 
              .fontWeight(400) 
              .opacity(0.6); 
          } 
        } 
        .justifyContent(FlexAlign.SpaceBetween) 
        .height(72) 
        .width('100%') 
        .padding({ left: '3.35%', right: '3.35%' }) 
        .backgroundColor(Color.White) 
        .borderRadius(24); 
      }.padding({ left: '3.35%', right: '3.35%' }); 
    } 
    .height('100%').width('100%').backgroundColor('#f1f3f5'); 
  } 
}