工具类

import { bundleManager, wantAgent } from '@kit.AbilityKit'
import { process } from '@kit.ArkTS'
import { avSession } from '@kit.AVSessionKit'
import { backgroundTaskManager } from '@kit.BackgroundTasksKit'

class BackgroundRunningManager {
  // 申请长时任务
  async startBackgroundRunning() {
    const context = getContext()
    // 重点1: 提供音频后台约束能力，音频接入AVSession后，可以进行后台音频播放
    const session = await avSession.createAVSession(context, 'guardianSession', 'audio')
    await session.activate()
    // 获取 bundle 应用信息
    const bundleInfo = bundleManager.getBundleInfoForSelfSync(bundleManager.BundleFlag.GET_BUNDLE_INFO_WITH_APPLICATION)
    // 通过wantAgent模块下getWantAgent方法获取WantAgent对象
    const wantAgentObj = await wantAgent.getWantAgent({
      // 添加需要被拉起应用的bundleName和abilityName
      wants: [{ bundleName: bundleInfo.name, abilityName: "EntryAbility" }],
      // 使用者自定义的一个私有值
      requestCode: 0,
     })
    // 重点2: 创建后台任务
    await backgroundTaskManager.startBackgroundRunning(context,
       backgroundTaskManager.BackgroundMode.AUDIO_PLAYBACK, wantAgentObj)
  }

  // 停止后台任务
  async stopBackgroundRunning() {
    backgroundTaskManager.stopBackgroundRunning(getContext())
  }
}

export const backgroundRunningManager = new BackgroundRunningManager()

配置后台播放

"abilities": [
  {
  
    "backgroundModes": [
      // 音频播放
      "audioPlayback"
     ],
  
  }
],
"requestPermissions": [
  {
    "name":  "ohos.permission.KEEP_BACKGROUND_RUNNING",
  }
],

Index.ets

import { audio } from '@kit.AudioKit';
import { media } from '@kit.MediaKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { common } from '@kit.AbilityKit';
import { backgroundRunningManager } from '../utils/A';

async function play(fileNames: string[]) {
  backgroundRunningManager.startBackgroundRunning()


  // 执行应用本身业务
  let index = 0 //指向当前播放的数据
  let soundIds: number[] = []
  let streamIds: number[] = []

  let playParameters: media.PlayParameters = {
    loop: 0, // 不循环
    rate: audio.AudioRendererRate.RENDER_RATE_NORMAL, // 正常倍速（1倍速） 只能 1倍速 2倍速 0.5倍速
    leftVolume: 0.5, // range = 0.0-1.0
    rightVolume: 0.5, // range = 0.0-1.0
    priority: 0, // 最低优先级
  };

  // audioRenderInfo中的参数usage取值为STREAM_USAGE_UNKNOWN，STREAM_USAGE_MUSIC，STREAM_USAGE_MOVIE，
  // STREAM_USAGE_AUDIOBOOK时，SoundPool播放短音时为混音模式，不会打断其他音频播放。
  let audioRendererInfo: audio.AudioRendererInfo = {
    usage: audio.StreamUsage.STREAM_USAGE_MUSIC,
    rendererFlags: 1
  };
  //创建soundPool实例
  let soundPool = await media.createSoundPool(5, audioRendererInfo);
  //注册监听
  // 加载完成回调
  soundPool.on('loadComplete', (soundId_: number) => {
    //全部加载完成
    if(soundId_ === fileNames.length){
      // 开始播放，这边play也可带播放播放的参数PlayParameters，请在音频资源加载完毕，即收到loadComplete回调之后再执行play操作
      soundPool.play(soundIds[index], playParameters, (error, streamID: number) => {
        if (error) {
          console.info(`play sound Error: errCode is ${error.code}, errMessage is ${error.message}`)
        } else {
          streamIds.push(streamID)
        }
      });
    }
    console.info('loadComplete, soundId: ' + soundId_);
  })
  // 播放完成回调
  soundPool.on('playFinished', async () => {
    console.info("receive play finished message");
    index++
    if(index < fileNames.length){
      // 播放下一个
      soundPool.play(soundIds[index], playParameters, (error, streamID: number) => {
        if (error) {
          console.info(`play sound Error: errCode is ${error.code}, errMessage is ${error.message}`)
        } else {
          streamIds.push(streamID)
        }
      });
    }else{
      //释放资源
      // 终止指定流的播放
      for (let streamId of streamIds) {
        await soundPool.stop(streamId);
      }
      // 卸载音频资源
      for (const soundId of soundIds) {
        await soundPool.unload(soundId);
      }
      //关闭监听
      soundPool.off('loadComplete');
      soundPool.off('playFinished');
      soundPool.off('error');
      // 释放SoundPool
      await soundPool.release();
      //关闭长时任务
      backgroundRunningManager.startBackgroundRunning()
    }

  })
  //错误监听
  soundPool.on('error', (error: BusinessError) => {
    console.info('error happened,message is :' + error.message);
  })

  for (let i = 0; i < fileNames.length; i++) {
    // 加载音频资源
    const file =
      AppStorage.get<common.UIAbilityContext>('UIContext')!.resourceManager.getRawFdSync(`audio/${fileNames[i]}`)
    let soundId = await soundPool.load(file.fd, file.offset, file.length);
    soundIds.push(soundId);
  }

}


@Entry
@Component
struct Page {
  @State message: string = 'Hello World';
  aboutToAppear(): void {
    //todo 放uiAbility中
    AppStorage.setOrCreate<common.UIAbilityContext>('UIContext', getContext(this) as common.UIAbilityContext)
  }
  build() {
    Column() {
      Row()
        .width(200)
        .backgroundColor(Color.Red)
        .aspectRatio(1)
        .blur(20)
      Button('121.45')
        .onClick(() => {
          //123.45
          //1B2S3D45Y
          let fileNames: string[] =
            ['start.mp3', '1.mp3','B.mp3','2.mp3','S.mp3','1.mp3','D.mp3','4.mp3','5.mp3','Y.mp3'];
          play(fileNames);
        });
    }
    .height('100%')
    .width('100%')
  }
}