HarmonyOS鸿蒙Next中创建AVSession之后在通知栏没有显示

AVSession播控中心，您可以参考示例：https://gitee.com/harmonyos_samples/media-provider，您想实现音乐播放器控制台在通知栏显示，需要做一个通知，在通知上添加几个按钮。当前通知可以通过设置actionButtons设置按键，规格当前最多三个按钮。

请参考如下链接：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-inner-notification-notificationrequest-V5

您截图这种，可以使用AVPlayer+AVSession实现，AVPlayer文档：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-media-V5#avplayer9，AVSession文档：https://developer.huawei.com/consumer/cn/doc/harmonyos-references-V5/js-apis-avsession-V5#avsession10，简易demo如下：

import { media } from '@kit.MediaKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { avSession } from '@kit.AVSessionKit';

const TAG = 'AVPlayerDemo';

@Entry
@Component
struct AVPlayerDemo {
  private surfaceId: string = ''; // surfaceId，用于关联XComponent与视频播放器
  private mXComponentController: XComponentController = new XComponentController();
  private avPlayer: media.AVPlayer | undefined = undefined;
  private currentAVSession: avSession.AVSession | undefined = undefined;
  private curSessionId: string = '';
  private avsessionController: avSession.AVSessionController | undefined = undefined;
  private playbackState: avSession.AVPlaybackState = {
    state: avSession.PlaybackState.PLAYBACK_STATE_PLAY, // 播放状态
    position: {
      elapsedTime: 0, // 已经播放的位置，以ms为单位
      updateTime: 0, // 应用更新当前位置的时间戳，以ms为单位
    },
    speed: 1.0, // 可选，默认是1.0，播放的倍速，按照应用内支持的speed进行设置，系统不做校验
    duration: 0, // 资源的时长，以ms为单位
    loopMode: avSession.LoopMode.LOOP_MODE_SEQUENCE, // 循环模式
  };

  aboutToAppear(): void {
    // 创建avplayer
    this.initAvPlayer()
    // 初始化AVSession
    this.createAVSession();
  }

  initAvPlayer() {
    media.createAVPlayer().then((avPlayer: media.AVPlayer) => {
      this.avPlayer = avPlayer;
      this.playerCallback(this.avPlayer);
      this.avPlayer.url = 'http://fotiletest2.oss-cn-hangzhou.aliyuncs.com/f86ee6ff04f94c4d922936faedbfca06';
    })
  }

  // 注册avplayer回调函数
  playerCallback(avPlayer: media.AVPlayer) {
    avPlayer.on('timeUpdate', (time: number) => {
      if (this.currentAVSession) {
        this.playbackState.position = {
          elapsedTime: time, // 已经播放的位置，以ms为单位
          updateTime: (new Date()).getTime(), // 应用更新当前位置的时间戳，以ms为单位
        };
        this.currentAVSession.setAVPlaybackState(this.playbackState);
      }
    })

    // error回调监听函数,当avPlayer在操作过程中出现错误时调用 reset接口触发重置流程
    avPlayer.on('error', (err: BusinessError) => {
      console.error(TAG, `Invoke avPlayer failed, code is ${err.code}, message is ${err.message}`);
      avPlayer.reset(); // 调用reset重置资源，触发idle状态
    })

    // 状态机变化回调函数
    avPlayer.on('stateChange', async (state: string, reason: media.StateChangeReason) => {
      switch (state) {
        case 'idle': // 成功调用reset接口后触发该状态机上报
          console.info(TAG, 'AVPlayer state idle called.');
          break;
        case 'initialized': // avplayer 设置播放源后触发该状态上报
          console.info(TAG, 'AVPlayer state initialized called.');
          avPlayer.surfaceId = this.surfaceId;
          avPlayer.prepare();
          break;
        case 'prepared': // prepare调用成功后上报该状态机
          console.info(TAG, 'AVPlayer state prepared called.');
          await this.startAVSession();
          break;
        case 'completed': // prepare调用成功后上报该状态机
          console.info(TAG, 'AVPlayer state completed called.');
          break;
        case 'playing': // play成功调用后触发该状态机上报
          console.info(TAG, 'AVPlayer state playing called.');
          break;
        case 'paused': // pause成功调用后触发该状态机上报
          console.info(TAG, 'AVPlayer state paused called.');
          break;
        case 'stopped': // stop接口成功调用后触发该状态机上报
          console.info(TAG, 'AVPlayer state stopped called.');
          break;
        case 'released':
          console.info(TAG, 'AVPlayer state released called.');
          break;
        default:
          console.info(TAG, 'AVPlayer state unknown called.');
          break;
      }
    })
  }

  async createAVSession() {
    await avSession.createAVSession(getContext(this), 'AVPlayerDemo', 'video').then((data: avSession.AVSession) => {
      console.info(`AVPlayerDemo CreateAVSession : SUCCESS : sessionId = ${data.sessionId}`);
      this.currentAVSession = data;
      this.curSessionId = data.sessionId;
      this.setAVSessionCallback(data);
    }).catch((err: BusinessError) => {
      console.error(`AVPlayerDemo CreateAVSession BusinessError: code: ${err.code}, message: ${err.message}`);
    });
  }

  setAVSessionCallback(curAvSession: avSession.AVSession) {
    // 播放
    curAvSession.on('play', () => {
      console.info(`AVPlayerDemo AVSession on play entry`);
      this.avPlayer?.play()
    });

    // 暂停
    curAvSession.on('pause', () => {
      console.info(`AVPlayerDemo AVSession on pause entry`);
      if (this.avPlayer) {
        this.avPlayer.pause();
      }
    });

    // 停止
    curAvSession.on('stop', () => {
      console.info(`AVPlayerDemo AVSession on stop entry`);
      this.avPlayer?.stop();
    });

    // 下一个
    curAvSession.on('playNext', () => {
      console.info(`AVPlayerDemo AVSession on playNext entry`);
    });

    // 上一个
    curAvSession.on('playPrevious', () => {
      console.info(`AVPlayerDemo AVSession on playPrevious entry`);
    });
  }

  async startAVSession() {
    if (!this.currentAVSession) {
      console.error('AVPlayerDemo currentAVSession is undefined.')
      return;
    }

    let metadata: avSession.AVMetadata = this.generateAVMetadata();

    await this.currentAVSession.setAVMetadata(metadata).then(() => {
      console.info(`AVPlayerDemo SetAVMetadata successfully`);
    }).catch((err: BusinessError) => {
      console.error(`AVPlayerDemo SetAVMetadata BusinessError: code: ${err.code}, message: ${err.message}`);
    });

    this.playbackState.state = avSession.PlaybackState.PLAYBACK_STATE_PREPARE;
    this.playbackState.duration = this.avPlayer?.duration;
    this.currentAVSession.setAVPlaybackState(this.playbackState);
    this.currentAVSession.getController().then((avcontroller: avSession.AVSessionController) => {
      this.avsessionController = avcontroller;
      console.info(`AVPlayerDemo GetController : SUCCESS : sessionid : ${avcontroller.sessionId}`);
    }).catch((err: BusinessError) => {
      console.error(`AVPlayerDemo GetController BusinessError: code: ${err.code}, message: ${err.message}`);
    });

    await this.currentAVSession.activate().then(() => {
      console.info(`AVPlayerDemo Activate : SUCCESS `);
    }).catch((err: BusinessError) => {
      console.error(`AVPlayerDemo Activate BusinessError: code: ${err.code}, message: ${err.message}`);
    });
  }

  private generateAVMetadata() {
    let metadata: avSession.AVMetadata = {
      assetId: "121278",
      title: "lose yourself",
      artist: "Eminem",
      author: "ST",
      album: "Slim shady",
      writer: "ST",
      composer: "ST",
      duration: this.avPlayer?.duration, // 媒体时长，单位毫秒（ms）
      mediaImage: '', // 图片的像素数据或者图片路径地址(本地路径或网络路径)
      subtitle: "8 Mile",
      description: "Rap",
      previousAssetId: "121277",
      nextAssetId: "121279"
    };
    return metadata;
  }

  build() {
    Column({ space: 20 }) {
      XComponent({
        id: 'xComponent',
        type: XComponentType.SURFACE,
        controller: this.mXComponentController
      })
        .onLoad(() => {
          this.mXComponentController.setXComponentSurfaceRect({
            offsetX: 0,
            offsetY: 0,
            surfaceWidth: 1920,
            surfaceHeight: 1080
          });
          this.surfaceId = this.mXComponentController.getXComponentSurfaceId()
        })
        .width('100%')
        .height('800px')

      Button("播放")
        .onClick(() => {
          this.avPlayer?.play()
        })
    }
    .height('100%')
    .width('100%')
  }
}