HarmonyOS鸿蒙Next中使用SoundPool播放音频，音频文件放在工程下的rawFile下，如何转化为参数uri？

用SoundPool实现音频播放功能。

1、调用createSoundPool方法创建SoundPool实例。

import media from '@ohos.multimedia.media';
import audio from '@ohos.multimedia.audio';
import { BusinessError } from '@ohos.base';

let soundPool: media.SoundPool;
let audioRendererInfo: audio.AudioRendererInfo = {
  usage : audio.StreamUsage.STREAM_USAGE_MUSIC,
  rendererFlags : 0
}

media.createSoundPool(5, audioRendererInfo).then((soundpool_: media.SoundPool) => {
  if (soundpool_ != null) {
    soundPool = soundpool_;
    console.info('create SoundPool success');
  } else {
    console.error('create SoundPool fail');
  }
}).catch((error: BusinessError) => {
  console.error(`soundpool catchCallback, error message:${error.message}`);
});
注册监听（资源加载完成，播放完成，错误类型监听）
soundPool.on('loadComplete', (soundId: number) => {
  console.info('loadComplete, soundId: ' + soundId);
});
soundPool.on('playFinished', () => {
  console.info("receive play finished message");
});
soundPool.on('error', (error) => {
  console.info('error happened,message is :' + error.message);
});
调用load方法进行音频资源加载。
可以传入uri或fd加载资源，此处使用传入uri的方式为例，更多方法请参考API文档。

const audioViewPicker = new picker.AudioViewPicker();
audioViewPicker.select(audioSelectOptions).then(async (audioSelectResult: Array<string>) => {
  urii = audioSelectResult[0];
  console.info('audioViewPicker.select to file succeed and uri is:' + urii);
  if(urii){
    await fs.open(urii, fs.OpenMode.READ_ONLY).then((file_: fs.File) => {
      let file=file_;
      console.info("file fd: " + file.fd);
      uri = 'fd://' + (file.fd).toString()
    }); // '/test_01.mp3' 作为样例，使用时需要传入文件对应路径。
    soundPool.load(uri).then((soundIdd: number) => {
      console.info('soundPool load uri success');
      soundId=soundIdd;
    }).catch((err: BusinessError) => {
      console.error('soundPool load failed and catch error is ' + err.message);
    })
  }

}).catch((err: BusinessError) => {
  console.error(`Invoke audioViewPicker.select failed, code is ${err.code}, message is ${err.message}`);
})

2、配置播放参数PlayParameters，并调用play方法播放音频。多次调用play播放同一个soundID，只会播放一次。

let PlayParameters: media.PlayParameters = {
  loop: 3, // 循环4次
  rate: audio.AudioRendererRate.RENDER_RATE_NORMAL, // 正常倍速
  leftVolume: 0.9, // range = 0.0-1.0
  rightVolume: 0.9, // range = 0.0-1.0
  priority: 3, // 最低优先级
}

// 开始播放,这边play也可带播放播放的参数PlayParameters
streamId = await soundPool.play(soundId,PlayParameters);
释放资源
async function release() {
  // 终止指定流的播放
  soundPool.stop(streamId);
  // 卸载音频资源
  await soundPool.unload(soundId);
  //关闭监听
  setOffCallback();
  // 释放SoundPool
  await soundPool.release();
}
//关闭监听
function setOffCallback() {
  soundPool.off('loadComplete');
  soundPool.off('playFinished');
  soundPool.off('error');
}