折叠屏音乐播放器案例

// TODO：知识点：FolderStack继承于Stack控件，通过upperItems字段识别指定id的组件，自动避让折叠屏折痕区后移到上半屏
FolderStack({ upperItems: [CommonConstants.FOLDER_STACK_UP_COMP_ID] }) {
    MusicPlayerInfoComp({ musicModel: this.musicModel, curFoldStatus: this.curFoldStatus })
        .id(CommonConstants.FOLDER_STACK_UP_COMP_ID)
    MusicPlayerCtrlComp({ musicModel: this.musicModel })
}

Image(this.musicModel.coverRes)
  .width(this.curImgSize)
  .height(this.curImgSize)
  .margin(20)
  .animation(this.attrAniCfg)
  .interpolation(ImageInterpolation.High)
  .draggable(false)

display.on('foldStatusChange', (curFoldStatus: display.FoldStatus) => {
    this.curFoldStatus = curFoldStatus;
    this.windowModel.updateMainWinPreferredOrientation(curFoldStatus);
})

// TODO：知识点：创建AVSession实例
this.session = await AVSessionManager.createAVSession(this.bindContext!, this.avSessionTag, this.avSessionType);
// TODO：知识点：注册AVSession事件
await this.registerSessionListener(eventListener);
// TODO：知识点：激活AVSession实例
await this.session.activate();

// 设置必要的媒体信息
let metadata: AVSessionManager.AVMetadata = {
  assetId: '0', // 由应用指定，用于标识应用媒体库里的媒体
  title: musicModel?.title,
  mediaImage: imagePixel,
  artist: musicModel?.singer,
  duration: musicModel?.totalTime,
  lyric: lrcStr
}
// TODO：知识点：设置AVSession元信息
this.session?.setAVMetadata(metadata).then(() => {
  logger.info(`SetAVMetadata successfully`);
}).catch((err: BusinessError) => {
  logger.error(`Failed to set AVMetadata. Code: ${err.code}, message: ${err.message}`);
});


// TODO：知识点：设置AVSession当前状态
this.session?.setAVPlaybackState(this.curState, (err) => {
  if (err) {
    console.error(`Failed to set AVPlaybackState. Code: ${err.code}, message: ${err.message}`);
  } else {
    console.info(`SetAVPlaybackState successfully`);
  }
});

let wantAgentInfo: wantAgent.WantAgentInfo = {
  // 点击通知后，将要执行的动作列表
  // 添加需要被拉起应用的bundleName和abilityName
  wants: [
    {
      bundleName: "com.north.cases",
      abilityName: "com.north.cases.EntryAbility"
    }
  ],
  // 指定点击通知栏消息后的动作是拉起ability
  actionType: wantAgent.OperationType.START_ABILITY,
  // 使用者自定义的一个私有值
  requestCode: 0,
  // 点击通知后，动作执行属性
  actionFlags: [wantAgent.WantAgentFlags.UPDATE_PRESENT_FLAG]
};
// 通过wantAgent模块下getWantAgent方法获取WantAgent对象
wantAgent.getWantAgent(wantAgentInfo).then((wantAgentObj: WantAgent) => {
  // TODO：知识点：设置后台任务类型，启动后台任务
  backgroundTaskManager.startBackgroundRunning(this.bindContext!,
    backgroundTaskManager.BackgroundMode.AUDIO_PLAYBACK, wantAgentObj).then(() => {
    // 此处执行具体的长时任务逻辑，如放音等。
    console.info(`Succeeded in operationing startBackgroundRunning.`);
    this.isBackgroundTaskRunning = true;
  }).catch((err: BusinessError) => {
    console.error(`Failed to operation startBackgroundRunning. Code is ${err.code}, message is ${err.message}`);
  });
});

// 播放
this.session?.on('play', () => {
  logger.info('avsession on play');
  eventListener.onPlay();
});
// 暂停
this.session?.on('pause', () => {
  logger.info('avsession on pause');
  eventListener.onPause();
});
// 停止
this.session?.on('stop', () => {
  logger.info('avsession on stop');
  eventListener.onStop();
});
// 下一首
this.session?.on('playNext', async () => {
  logger.info('avsession on playNext');
  eventListener.onPlayNext();
});
// 上一首
this.session?.on('playPrevious', async () => {
  logger.info('avsession on playPrevious');
  eventListener.onPlayPrevious();
});
// 拖进度
this.session?.on('seek', (position) => {
  logger.info('avsession on seek', position.toString());
  eventListener.onSeek(position);
});
// 标记喜好
this.session?.on('toggleFavorite', (assetId) => {
  logger.info('avsession on toggleFavorite', assetId);
});
// 播放循环模式切换
this.session?.on('setLoopMode', (mode) => {
  logger.info('avsession on setLoopMode', mode.toString());
  eventListener.onSetLoopMode();
});

onViewModelChanged() {
  const curMusiclyricsLine = this.viewModel.curMusiclyricsLine;
  this.lyricsScrollerCtrl.scrollToIndex(curMusiclyricsLine, true, ScrollAlign.CENTER);
}

switch (this.curLoopMode) {
  case AVSessionManager.LoopMode.LOOP_MODE_SINGLE: {
    this.seek(0);
    break;
  }

  case AVSessionManager.LoopMode.LOOP_MODE_LIST: {
    this.curMusicModelIndex = (this.curMusicModelIndex + 1) % this.musicModelArr.length;
    this.curMusicModelRaw = this.musicModelArr[this.curMusicModelIndex];
    await this.reset();
    await this.prepare(() => {
      this.play();
    });
    this.avsessionModel?.setSessionInfo(this.curMusicModelRaw);
    break;
  }

  case AVSessionManager.LoopMode.LOOP_MODE_SHUFFLE: {
    const randomVal: number = Decimal.random(1).e;
    let dieta: number = 1;
    while (dieta < this.musicModelArr.length - 1) {
      if (randomVal >= dieta - 1 / this.musicModelArr.length - 1 && randomVal < dieta / this.musicModelArr.length - 1) {
        break;
      }
      dieta++;
    }
    this.curMusicModelIndex = (this.curMusicModelIndex + dieta) % this.musicModelArr.length;
    this.curMusicModelRaw = this.musicModelArr[this.curMusicModelIndex];
    await this.reset();
    await this.prepare(() => {
      this.play();
    });
    this.avsessionModel?.setSessionInfo(this.curMusicModelRaw);
    break;
  }
}

foldablescreencases                  // har类型
|---common
|   |---constants
|   |    |---CommonConstants.ets     // 通用常量
|---components
|   |---MusicPlayerCtrlComp.ets      // 自定义组件-音乐播放器控制栏
|   |---MusicPlayerInfoComp.ets      // 自定义组件-音乐播放器歌曲详情展示
|---model
|   |---AVPlayerModel.ets            // 模型层-音频播放管理器 
|   |---AVSessionModel.ets           // 模型层-音频会话管理器
|   |---MusicModel.ets               // 模型层-音乐歌曲数据模型
|   |---WindowModel.ets              // 模型层-窗口管理器 
|---pages
|   |---MusicPlayerPage.ets          // 展示层-音乐播放器 
|---viewmodel
|   |---MusicPlayerViewModel.ets     // 控制层-音乐播放器控制器