x
 
<!DOCTYPE html>
<html>
<body>
<video id="myVideo" width="640" height="360" controls>
  <source src="/i/video/shanghai.mp4" type="video/mp4">
  <source src="/i/video/shanghai.ogg" type="video/ogg">
  您的浏览器不支持 video 标签。
</video>
<p>单击该按钮可更改视频的高度。</p>
<button onclick="myFunction()">试一试</button>
<script>
function myFunction() {
  document.getElementById("myVideo").height = "500";
}
</script>
</body>
</html>