Bootstrap下拉类
下拉菜单是可切换的上下文菜单，用于以列表格式显示链接。要使用下拉菜单，只需将下拉菜单包装在类.dropdown中。
您可以尝试运行以下代码以在Bootstrap中实现dropdown类
示例
<!DOCTYPE html>
<html>
<head>
<title>Bootstrap Example</title>
<link href = "/bootstrap/css/bootstrap.min.css" rel = "stylesheet">
<script src = "/scripts/jquery.min.js"></script>
<script src = "/bootstrap/js/bootstrap.min.js"></script>
</head>
<body>
<div class = "dropdown">
<button type = "button" class = "btn dropdown-toggle" id = "dropdownMenu1" data-toggle = "dropdown">
Subjects
<span class = "caret"></span>
</button>
<ul class = "dropdown-menu" role = "menu" aria-labelledby = "dropdownMenu1">
<li role = "presentation">
<a role = "menuitem" tabindex = "-1" href = "#">Java</a>
</li>
<li role = "presentation">
<a role = "menuitem" tabindex = "-1" href = "#">Data Mining</a>
</li>
<li role = "presentation">
<a role = "menuitem" tabindex = "-1" href = "#">
C++
</a>
</li>
<li role = "presentation" class = "divider"></li>
<li role = "presentation">
<a role = "menuitem" tabindex = "-1" href = "#">Separated link</a>
</li>
</ul>
</div>
</body>
</html>