如何写一个简单的鼠标滑动过的二级菜单

 1 <!DOCTYPE HTML>
 2 <html lang="en-US">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title></title>
 6 </head>
 7 <body>
 8 <style type="text/css" >    
 9 .menu{    
10     margin:0px auto;    
11     width:404px;    
12     height:21px;    
13 }    
14 .menu ul{    
15     margin:0px;    
16     padding:0px;    
17 }    
18 .menu ul li{    
19     position:relative;    
20     float:left;    
21     list-style:none;    
22     padding:2px;    
23     border:1px dotted;    
24     font-size:14px;    
25     width:95px;    
26     text-align: center;    
27     margin:0px;
28     background:#999999;    
29 }    
30 .menu ul li ul{    
31     display:none;    
32 }    
33 .menu ul li:hover ul{    
34     display:block;    
35     position: absolute; left: 0px; top: 21px;    
36 }
37 </style>    
38 <body>       
39 <p>下面是一个导航条</p>    
40 <div class="menu">    
41     <ul>    
42         <li><a href="#">首页</a></li>    
43         <li>
44             <a href="#">新闻中心</a>    
45             <ul>    
46                 <li><a href="1#">新手入门</a></li>    
47                 <li><a href="2#">视频教程</a></li>    
48                 <li><a href="3#">常见问题</a></li>    
49             </ul>    
50         </li>    
51         <li>
52             <a href="#">学习课程</a>    
53             <ul>    
54                 <li><a href="1#">新手入门</a></li>    
55                 <li><a href="2#">视频教程</a></li>    
56                 <li><a href="3#">常见问题</a></li>    
57             </ul>    
58         </li>    
59         <li><a href="#">联系我们</a></li>    
60     </ul>    
61 </div>    
62 </body>
63 </html>
原文地址:https://www.cnblogs.com/lizhaoyao/p/5332679.html