<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>清楚浮动</title>
<style>
*{padding:0px; margin:0px;}
ul{border:3px solid #F00;}
ul li{width:50px; height:50px; float:left; background-color:#00F; list-style:none; margin-right:10px;}
/*
---------------------------------------------
采用伪类:after进行后续空制的高度位零的伪类层清除
---------------------------------------------
*/
.clearfix_after{zoom:1;}
.clearfix_after:after{
content:"";
display:block;
height:0;
line-height:0;
clear:both;
visibility:hidden;
}
</style>
</head>
<body>
<ul class="clearfix_after">
<li></li>
<li></li>
<li></li>
<li></li>
<li></li>
</ul>
</body>
</ html>
