微信小程序获取音频时长与实时获取播放进度问题

audioPlayed: function () {
  myAudio.play()
  setTieout(() => {
    myAudio.onTimeUpdate(() => {
      console.log(myAudio.duration)  //总时长
      console.log(myAudio.currentTime)  //当前播放进度
    })
  }, 500)
}

audioPlayed: function () {
  myAudio.play()
  setTieout(() => {
    myAudio.currentTime
    myAudio.onTimeUpdate(() => {
      console.log(myAudio.duration)  //总时长
      console.log(myAudio.currentTime)  //当前播放进度
    })
  }, 500)
}

onLoad: function () {
    bgM = wx.createInnerAudioContext();
    bgM.src = 'https://upyun.lesson.bbwansha.com/dub/user/2.mp3';
    console.log(bgM.duration);//0
    bgM.onCanplay(()=>{
       console.log(bgM.duration)//0
    })
    bgM.play();
    bgM.onPlay(()=>{
       console.log(bgM.duration)//0
    })
    setTimeout(()=>{
      console.log(bgM.duration)//2.795102
    },1000)
},