audio 的 canplaythrough 事件表示的是音頻能夠不停頓地一直播放,可是這個事件為什么發(fā)生在表示瀏覽器正在下載指定的音頻的事件之前(progress事件),而且這兩個事件為什么都觸發(fā)了不止一次?
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Audio-demo</title>
</head>
<body>
<audio id="audio-demo" src="http://www.sample-videos.com/audio/mp3/india-national-anthem.mp3" controls preload="metadata">
</audio>
<script>
var audio = document.getElementById('audio-demo');
audio.onloadstart = function() {
console.log('loadstart');
}
audio.onprogress = function() {
console.log('progress');
}
audio.oncanplaythrough = function() {
console.log('canplaythrough');
}
</script>
</body>
</html>