参考：http://www.mscto.com/JavaScript/11582904.html
<html>
<head>
<script language="javascript">
function clear(){
Source=document.body.firstChild.data;
document.open();
document.close();
document.title="看不到源代码";
document.body.innerHTML=Source;
}
</script>
</head>
<body onload=clear()>
</body>
</html>
破解办法在地址栏中输入javascript:alert(document.documentElement.outerHTML);