问题描述
<video id="myVideo">
<source src="">
</video>
<script>
var vid = document.getElementById("myVideo");
alert(vid.duration);
</script>
解决方法
您需要等待文件的元数据加载:
var vid = document.getElementById("myVideo");
vid.addEventListener('loadedmetadata',function() {
console.log(vid.duration);
});