<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Bootstrap 下拉菜单</title>
<link rel="stylesheet" href="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/css/bootstrap.min.css">
</head>
<body>
<div class="container">
<h2>下拉菜单</h2>
<div class="dropup">
<button class="btn btn-default dropdown-toggle" type="button" id="menu1" data-toggle="dropdown">
教程
<span class="caret"></span>
</button>
<ul class="dropdown-menu" role="menu" aria-labelledby="menu1">
<li role="presentation"><a role="menuitem" tabindex="-1" href="#">HTML</a></li>
<li role="presentation"><a role="menuitem" tabindex="-1" href="#">CSS</a></li>
<li role="presentation"><a role="menuitem" tabindex="-1" href="#">JavaScript</a></li>
<li role="presentation" class="divider"></li>
<li role="presentation"><a role="menuitem" tabindex="-1" href="#">关于我们</a></li>
</ul>
</div>
</div>
<script src="http://cdn.static.runoob.com/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/js/bootstrap.min.js"></script>
</body>
</html>