使用AVPlayer開發(fā)音頻播放功能

import media from '@ohos.multimedia.media';
import fs from '@ohos.file.fs';
import common from '@ohos.app.ability.common';

export class AVPlayerDemo {
  private avPlayer;
  private count: number = 0;

  // 注冊avplayer回調(diào)函數(shù)
  setAVPlayerCallback() {
    // seek操作結(jié)果回調(diào)函數(shù)
    this.avPlayer.on('seekDone', (seekDoneTime) => {
      console.info(`AVPlayer seek succeeded, seek time is ${seekDoneTime}`);
    })
    // error回調(diào)監(jiān)聽函數(shù),當avPlayer在操作過程中出現(xiàn)錯誤時調(diào)用reset接口觸發(fā)重置流程
    this.avPlayer.on('error', (err) => {
      console.error(`Invoke avPlayer failed, code is ${err.code}, message is ${err.message}`);
      this.avPlayer.reset(); // 調(diào)用reset重置資源，觸發(fā)idle狀態(tài)
    })
    // 狀態(tài)機變化回調(diào)函數(shù)
    this.avPlayer.on('stateChange', async (state, reason) => {
      switch (state) {
        case 'idle': // 成功調(diào)用reset接口后觸發(fā)該狀態(tài)機上報
          console.info('AVPlayer state idle called.');
          this.avPlayer.release(); // 調(diào)用release接口銷毀實例對象
          break;
        case 'initialized': // avplayer 設(shè)置播放源后觸發(fā)該狀態(tài)上報
          console.info('AVPlayerstate initialized called.');
          this.avPlayer.prepare().then(() => {
            console.info('AVPlayer prepare succeeded.');
          }, (err) => {
            console.error(`Invoke prepare failed, code is ${err.code}, message is ${err.message}`);
          });
          break;
        case 'prepared': // prepare調(diào)用成功后上報該狀態(tài)機
          console.info('AVPlayer state prepared called.');
          this.avPlayer.play(); // 調(diào)用播放接口開始播放
          break;
        case 'playing': // play成功調(diào)用后觸發(fā)該狀態(tài)機上報
          console.info('AVPlayer state playing called.');
          if (this.count !== 0) {
            console.info('AVPlayer start to seek.');
            this.avPlayer.seek(this.avPlayer.duration); //seek到音頻末尾
          } else {
            this.avPlayer.pause(); // 調(diào)用暫停接口暫停播放
          }
          this.count++;
          break;
        case 'paused': // pause成功調(diào)用后觸發(fā)該狀態(tài)機上報
          console.info('AVPlayer state paused called.');
          this.avPlayer.play(); // 再次播放接口開始播放
          break;
        case 'completed': // 播放結(jié)束后觸發(fā)該狀態(tài)機上報
          console.info('AVPlayer state completed called.');
          this.avPlayer.stop(); //調(diào)用播放結(jié)束接口
          break;
        case 'stopped': // stop接口成功調(diào)用后觸發(fā)該狀態(tài)機上報
          console.info('AVPlayer state stopped called.');
          this.avPlayer.reset(); // 調(diào)用reset接口初始化avplayer狀態(tài)
          break;
        case 'released':
          console.info('AVPlayer state released called.');
          break;
        default:
          console.info('AVPlayer state unknown called.');
          break;
      }
    })
  }

  // 以下demo為使用fs文件系統(tǒng)打開沙箱地址獲取媒體文件地址并通過url屬性進行播放示例
  async avPlayerUrlDemo() {
    // 創(chuàng)建avPlayer實例對象
    this.avPlayer = await media.createAVPlayer();
    // 創(chuàng)建狀態(tài)機變化回調(diào)函數(shù)
    this.setAVPlayerCallback();
    let fdPath = 'fd://';
    // 通過UIAbilityContext獲取沙箱地址filesDir，以下為Stage模型獲方式，如需在FA模型上獲取請參考《訪問應(yīng)用沙箱》獲取地址
    let context = getContext(this) as common.UIAbilityContext;
    let pathDir = context.filesDir;
    let path = pathDir + '/01.mp3';
    // 打開相應(yīng)的資源文件地址獲取fd，并為url賦值觸發(fā)initialized狀態(tài)機上報
    let file = await fs.open(path);
    fdPath = fdPath + '' + file.fd;
    this.avPlayer.url = fdPath;
  }

  // 以下demo為使用資源管理接口獲取打包在HAP內(nèi)的媒體資源文件并通過fdSrc屬性進行播放示例
  async avPlayerFdSrcDemo() {
    // 創(chuàng)建avPlayer實例對象
    this.avPlayer = await media.createAVPlayer();
    // 創(chuàng)建狀態(tài)機變化回調(diào)函數(shù)
    this.setAVPlayerCallback();
    // 通過UIAbilityContext的resourceManager成員的getRawFd接口獲取媒體資源播放地址
    // 返回類型為{fd,offset,length},fd為HAP包fd地址，offset為媒體資源偏移量，length為播放長度
    let context = getContext(this) as common.UIAbilityContext;
    let fileDescriptor = await context.resourceManager.getRawFd('01.mp3');
    // 為fdSrc賦值觸發(fā)initialized狀態(tài)機上報
    this.avPlayer.fdSrc = fileDescriptor;
    this.isSeek = false; // 不支持seek操作
  }
}