简单教程
提交运行
代码编辑器：
<!DOCTYPE htm> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"> <script src="https://cdn.bootcss.com/jquery/1.12.4/jquery.js"></script> <script src="https://cdn.bootcss.com/bootstrap/3.3.7/js/bootstrap.min.js"></script> <style>body {margin:50px 20px}</style> <h2>向上下拉菜单</h2> <p>.dropup 类用于指定一个向上的下拉菜单。</p> <p>.dropdown-menu 类用于创建下拉菜单。</p> <div class="dropup"> <button class="btn btn-default dropdown-toggle" type="button" id="menu1" data-toggle="dropdown">前端 <span class="caret"></span></button> <ul class="dropdown-menu" role="menu" aria-labelledby="menu1"> <li role="presentation"><a role="menuitem" tabindex="-1" href="#">HTML 5</a></li> <li role="presentation"><a role="menuitem" tabindex="-1" href="#">CSS 3</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="#">jQuery</a></li> </ul> </div>
运行结果：