<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Bootstrap 按钮下拉菜单-原始</title>
<link rel="stylesheet" href="http://cdn.static.runoob.com/libs/bootstrap/3.3.7/css/bootstrap.min.css">
</head>
<body>
<div class="container">
<div class="btn-group">
<button class="btn btn-primary dropdown-toggle" data-toggle="dropdown">
原始btn-primary
<span class="caret"></span>
</button>
<ul class="dropdown-menu" role="menu">
<li><a href="#">功能 1</a></li>
<li><a href="#">功能 2</a></li>
<li><a href="#">功能 3</a></li>
<li class="divider"></li>
<li><a href="#">功能 4</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>