<!DOCTYPE html>
<html>
<head>
<title>Bootstrap实例</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://apps.bdimg.com/libs/bootstrap/3.3.0/css/bootstrap.min.css">
<script src="https://libs.baidu.com/jquery/2.1.4/jquery.min.js"></script>
<script src="https://apps.bdimg.com/libs/bootstrap/3.3.0/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<h3>Pills With Dropdown Menu</h3>
<ul class="nav nav-pills nav-stacked">
<li class="active"><a href="#">Home</a></li>
<li class="dropdown">
<a class="dropdown-toggle" data-toggle="dropdown" href="#">Menu 1 <span class="caret"></span></a>
<ul class="dropdown-menu">
<li><a href="#">Submenu 1-1</a></li>
<li><a href="#">Submenu 1-2</a></li>
<li><a href="#">Submenu 1-3</a></li>
</ul>
</li>
<li><a href="#">Menu 2</a></li>
<li><a href="#">Menu 3</a></li>
</ul>
</div>
</body>
</html>