<html>
<body>
<p>点击按钮创建 VIDEO 元素，一个 preload 设置为 "none", 另外一个 preload 设置为 "auto".</p>
<button onclick="myFunction('none')">视频不预加载</button>
<button onclick="myFunction('auto')">视频预加载</button>
<br>
<script>
function myFunction(p)
{
var x = document.createElement("VIDEO");
x.setAttribute("controls", "controls");
var y = document.createElement("SOURCE");
y.setAttribute("src", "movie.mp4");
y.setAttribute("type", "video/mp4");
x.appendChild(y);
var z = document.createElement("SOURCE");
z.setAttribute("src", "movie.ogg");
z.setAttribute("type", "video/ogg");
x.appendChild(z);
// 设置 preload 属性:
x.preload=p;
document.body.appendChild(x);
}
</script>
</body>
</html>