HarmonyOS鸿蒙Next中想实现点击触发音效，但是根据指南写出来的代码，一直没声音无法实现

HarmonyOS鸿蒙Next中想实现点击触发音效，但是根据指南写出来的代码，一直没声音无法实现 想实现点击触发音效，但是根据指南写出来的代码，一直没声音无法实现。求助！代码附在下面:

Index.ets

import { MyPreferencesUtil } from '../MyPreferencesUtil'
import { AVPlayerDemo } from '../AVPlayerDemo'
@Entry
@Component

struct Index {
  @State Food:string = ''
  @State array:Array<string> = MyPreferencesUtil.getInstance().mUserInfo.array //['烤冷面','煎饼果子','粥','包子','芙蓉卷','寿司','兰州拉面','馋嘴鱼','香肉拌饭','馄饨','盅盅面','米村拌饭','米线','清补凉','螺蛳粉'];
  @State num:number = Math.floor(Math.random()*this.array.length);
  @State flag:Boolean = false
  @State currentIndex: number = 0;
  @State value_sub:string=''
  @State value_de:string=''
  @State display_a:string = ''
  avp: AVPlayerDemo = new AVPlayerDemo()
  private tabsController: TabsController = new TabsController();

  @Builder TabBuilder(title: string, targetIndex: number, selectedImg: Resource, normalImg: Resource) {
    Column() {
      Image(this.currentIndex === targetIndex ? selectedImg : normalImg)
        .size({ width: 25, height: 25 })
      Text(title)
        .fontColor(this.currentIndex === targetIndex ? '#1698CE' : '#6B6B6B')
    }
    .width('100%')
    .height(50)
    .justifyContent(FlexAlign.Center)
    .onClick(() => {
      this.currentIndex = targetIndex;
      this.tabsController.changeIndex(this.currentIndex);
    })
  }

  build() {
    Tabs({ barPosition: BarPosition.End, controller: this.tabsController }) {
      TabContent() {
        Column(){
          Button('启动')
            .width("180vp")
            .height("80vp")
            .offset({ x: "0vp", y: "500vp" })
            .onClick(()=>{
              this.num = Math.floor(Math.random()*this.array.length);
              this.display_a = this.array[this.num]
              this.avp.avPlayerFdSrcDemo()
            })
          Text(this.display_a)
            .fontSize(70)
            .width("500vp")
            .height("100vp")
            .offset({ x: "0vp", y: "200vp" })
            .textAlign(TextAlign.Center)
        }.width('100%').height('100%').backgroundColor('#FFFFFF')
      }
      .tabBar(this.TabBuilder('大转盘', 0, $r('app.media.up'), $r('app.media.down')))

      TabContent() {
        Column(){
          TextInput({ placeholder: '请输入想要添加的菜品' }).margin({top:20,bottom:10})
            .onChange((value:string)=>{
              this.value_sub = value
              //this.array.push(value)
            })
            .borderRadius(10)
          Button('菜品提交')
            .onClick(()=>{
              this.array.push(this.value_sub)
              MyPreferencesUtil.saveData()
            })
            .margin({top:10,bottom:10})
          TextInput({ placeholder: '请输入想要删除的菜品' }).margin({top:20,bottom:10})
            .onChange((value:string)=>{
              this.value_de = value
            })
            .borderRadius(10)
          Button('菜品删除')
            .onClick(()=>{
              if(this.array.indexOf(this.value_de) === -1){

              }
              else{
                this.array.splice(this.array.indexOf(this.value_de),1)
                MyPreferencesUtil.saveData()
              }
            })
            .margin({top:10,bottom:10})
          List({ space: this.array.length }) {
            ForEach(this.array, (item: number) =>{
              ListItem() {
                Text(`${item}`)
                  .width('50%')
                  .height(50)
                  .fontSize(20)
                  .fontColor(Color.White)
                  .textAlign(TextAlign.Center)
                  .borderRadius(10)
                  .backgroundColor(0x007DFF)
                  .offset({y: '400'})
              }
            }, item => item)
          }.listDirection(Axis.Horizontal).margin({top:-20})
        }.width('100%').height('100%').backgroundColor('#FFFFFF')
      }
      .tabBar(this.TabBuilder('设置', 1, $r('app.media.up'), $r('app.media.down')))
    }
    .barWidth('100%')
    .barHeight(50)
    .onChange((index: number) => {
      this.currentIndex = index;
    })
  }
}

AVPlayerDemo.ets

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 isSeek: boolean = true; // 用于区分模式是否支持seek操作
  private count: number = 0;

  // 注册avplayer回调函数
  setAVPlayerCallback() {
    // seek操作结果回调函数
    this.avPlayer.on('seekDone', (seekDoneTime) => {
      console.info(`AVPlayer seek succeeded, seek time is ${seekDoneTime}`);
    })
    // 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
    this.avPlayer.on('error', (err) => {
      console.error(`Invoke avPlayer failed, code is ${err.code}, message is ${err.message}`);
      this.avPlayer.reset(); // 调用reset重置资源，触发idle状态
    })
    // 状态机变化回调函数
    this.avPlayer.on('stateChange', async (state, reason) => {
      switch (state) {
        case 'idle': // 成功调用reset接口后触发该状态机上报
          console.info('AVPlayer state idle called.');
          this.avPlayer.release(); // 调用release接口销毁实例对象
          break;
        case 'initialized': // avplayer 设置播放源后触发该状态上报
          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调用成功后上报该状态机
          console.info('AVPlayer state prepared called.');
          this.avPlayer.play(); // 调用播放接口开始播放
          break;
        case 'playing': // play成功调用后触发该状态机上报
          console.info('AVPlayer state playing called.');
          if (this.count !== 0) {
            console.info('AVPlayer start to seek.');
            this.avPlayer.seek(this.avPlayer.duration); //seek到音频末尾
          } else {
            this.avPlayer.pause(); // 调用暂停接口暂停播放
          }
          this.count++;
          break;
        case 'paused': // pause成功调用后触发该状态机上报
          console.info('AVPlayer state paused called.');
          this.avPlayer.play(); // 再次播放接口开始播放
          break;
        case 'completed': // 播放结束后触发该状态机上报
          console.info('AVPlayer state completed called.');
          this.avPlayer.stop(); //调用播放结束接口
          break;
        case 'stopped': // stop接口成功调用后触发该状态机上报
          console.info('AVPlayer state stopped called.');
          this.avPlayer.reset(); // 调用reset接口初始化avplayer状态
          break;
        case 'released':
          console.info('AVPlayer state released called.');
          break;
        default:
          console.info('AVPlayer state unknown called.');
          break;
      }
    })
  }

  // 以下demo为使用fs文件系统打开沙箱地址获取媒体文件地址并通过url属性进行播放示例
  async avPlayerUrlDemo() {
    // 创建avPlayer实例对象
    this.avPlayer = await media.createAVPlayer();
    // 创建状态机变化回调函数
    this.setAVPlayerCallback();
    let fdPath = 'fd://';
    // 通过UIAbilityContext获取沙箱地址filesDir，以下为Stage模型获方式，如需在FA模型上获取请参考《访问应用沙箱》获取地址
    let context = getContext(this) as common.UIAbilityContext;
    let pathDir = context.filesDir;
    let path = pathDir + '/01.mp3';
    // 打开相应的资源文件地址获取fd，并为url赋值触发initialized状态机上报
    let file = await fs.open(path);
    fdPath = fdPath + '' + file.fd;
    this.avPlayer.url = fdPath;
  }

  // 以下demo为使用资源管理接口获取打包在HAP内的媒体资源文件并通过fdSrc属性进行播放示例
  async avPlayerFdSrcDemo() {
    // 创建avPlayer实例对象
    this.avPlayer = await media.createAVPlayer();
    // 创建状态机变化回调函数
    this.setAVPlayerCallback();
    // 通过UIAbilityContext的resourceManager成员的getRawFd接口获取媒体资源播放地址
    // 返回类型为{fd,offset,length},fd为HAP包fd地址，offset为媒体资源偏移量，length为播放长度
    let context = getContext(this) as common.UIAbilityContext;
    let fileDescriptor = await context.resourceManager.getRawFd('1.mp3');
    // 为fdSrc赋值触发initialized状态机上报
    this.avPlayer.fdSrc = fileDescriptor;
    this.isSeek = false; // 不支持seek操作
  }
}