javascript - HTML5 音频 - 测试无效状态错误（或 Dom 异常 11）

Question

我正在动态创建音频文件并动态更改源。但是，在我更改 src 并尝试更改 currentTime 之后，我总是会收到 Invalid state 错误。你如何进行测试？或者更好地在它准备好时触发一个事件，然后调用 currentTime 来改变它的音频位置。

this.doneLoading = function(aTime){

    try{
        this.mAudioPlayer.currentTime = aTime / 1000.0;
    }catch(err){
        console.log( err );
    }
    this.mAudioPlayer.play();   
}

this.playAtTime = function(aTime) {
    Debug("play at time audio: " + aTime);
    Debug("this.mAudioPlayer.currentTime: " + this.mAudioPlayer.currentTime);

     this.startTime = aTime;

    if (this.mAudioPlayer.src != this.mAudioSrc) {
        this.mAudioPlayer = new Audio();
        this.mAudioPlayer.src = this.mAudioSrc;
        this.mAudioPlayer.load();
        this.mAudioPlayer.play();
        this.mAudioPlayer.addEventListener('canplaythrough', this.doneLoading(aTime), false );
    }
    else if ((isChrome() || isMobileSafari()) && aTime == 0) {
        this.mAudioPlayer.load();
        this.mAudioPlayer.currentTime = aTime / 1000.0;
        this.mAudioPlayer.play();
        Debug("Reloading audio");
    }else{

        this.mAudioPlayer.currentTime = aTime / 1000.0;
        this.mAudioPlayer.play();
    }       



};

Answer 1

对于那些真正需要测试来防止这种无效状态错误的人，你可以试试这个：

if(this.readyState > 0)
    this.currentTime = aTime;

无论如何似乎对我有用:)

Answer 2

您没有将函数引用传递给 addEventListener - 您正在调用内联函数。doneLoading ()函数立即执行（在文件加载之前）并且浏览器正确地抛出一个 INVALID_STATE_ERR：

this.mAudioPlayer.addEventListener('canplaythrough', this.doneLoading(aTime), false );

尝试传入函数引用。像这样：

this.mAudioPlayer.addEventListener('loadedmetadata',function(){
    this.currentTime = aTime / 1000.0;
}, false );