​x
 
<!DOCTYPE html> 
<html> 
<body> 
​
<button onclick="enablePreload()" type="button">启用预加载</button>
<button onclick="disablePreload()" type="button">禁用预加载</button>
<button onclick="checkPreload()" type="button">检查预加载状态</button>
<br />
<br />
<video id="video1" controls="controls">
  <source src="/example/html5/mov_bbb.mp4" type="video/mp4">
  <source src="/example/html5/mov_bbb.ogg" type="video/ogg">
  Your browser does not support HTML5 video.
</video>
​
<script>
myVid=document.getElementById("video1");
function enablePreload()
  { 
  myVid.preload="auto";
  } 
function disablePreload()
  { 
  myVid.preload="none";
  } 
function checkPreload()
  { 
  alert(myVid.preload);
  } 
</script> 
​
</body>
</html>
​