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<!DOCTYPE html> 
<html> 
<head> 
<meta charset="utf-8"> 
<title>Fmpq教程(fmpq.com)</title> 
</head> 
<body> 
<video id="myVideo" width="320" height="240" controls>
    <source src="movie.mp4" type="video/mp4">
    <source src="movie.ogg" type="video/ogg">
    您的浏览器不支持 video 标签。
</video>
<p>点击按钮获取或色织视频的音量。</p>
<button onclick="getVolume()" type="button">音量是多少?</button>
<button onclick="setHalfVolume()" type="button">设置音量值为 0.2</button>
<button onclick="setFullVolume()" type="button">设置音量值为 1.0</button>
<script>
var x = document.getElementById("myVideo");
function getVolume(){ 
    alert(x.volume);
} 
function setHalfVolume(){ 
    x.volume = 0.2;
} 
function setFullVolume(){ 
    x.volume = 1.0;
} 
</script> 
</body> 
</html>