复制下来根本没用，改了引用的链接的了，缩小屏幕会把右边的导航往下挤
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>下拉菜单</title>
<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css">
<script src="https://cdn.static.runoob.com/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
<style>
body{
padding:500px;
}
</style>
</head>
<body>
<!--代码-->
<div class="navbar navbar-default" role="navigation">
<div class="navbar-header">
<!-- .navbar-toggle样式用于toggle收缩的内容，即nav-collapse collapse样式所在元素 -->
<button class="navbar-toggle" type="button" data-toggle="collapse" data-target=".navbar-responsive-collapse">
<span class="sr-only">Toggle Navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<!-- 确保无论是宽屏还是窄屏，navbar-brand都显示 -->
<a href="##" class="navbar-brand">慕课网</a>
</div>
<!-- 屏幕宽度小于768px时，div.navbar-responsive-collapse容器里的内容都会隐藏，显示icon-bar图标，当点击icon-bar图标时，再展开。屏幕大于768px时，默认显示。 -->
<div class="collapse navbar-collapse navbar-responsive-collapse">
<ul class="nav navbar-nav">
<li class="active"><a href="##">网站首页</a></li>
<li><a href="##">系列教程</a></li>
<li><a href="##">名师介绍</a></li>
<li><a href="##">成功案例</a></li>
<li><a href="##">关于我们</a></li>
</ul>
</div>
</div>
</body>
</html>
