<html>
<head>
<title>Bootstrap 实例 - 下拉菜单标题</title>
<link href="https://libs.baidu.com/bootstrap/3.0.3/css/bootstrap.min.css" rel="stylesheet">
<script src="https://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
<script src="https://libs.baidu.com/bootstrap/3.0.3/js/bootstrap.min.js"></script>
</head>
<body>
<div class="dropdown">
<button type="button" class="btn dropdown-toggle" id="dropdownMenu1" data-toggle="dropdown">
主题
<span class="caret"></span>
</button>
<ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu1">
<li role="presentation" class="dropdown-header">下拉菜单标题</li>
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#">Java</a>
</li>
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#">数据挖掘</a>
</li>
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#">
数据通信/网络
</a>
</li>
<li role="presentation" class="divider">
<li role="presentation" class="dropdown-header">下拉菜单标题</li>
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#">分离的链接</a>
</li>
</ul>
</div>
</body>
</html>