Bootstrap - 下拉菜单插件

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使用下拉菜单插件，您可以将下拉菜单添加到任何组件，例如导航栏、选项卡、药丸和按钮。

如果您想单独包含此插件的功能，则需要 dropdown.js。否则，如在章节 Bootstrap 插件概述 中所述，您可以包含 bootstrap.js 或最小化的 bootstrap.min.js。

用法

您可以切换下拉菜单插件的隐藏内容 -

• 通过数据属性 - 向链接或按钮添加 data-toggle = "dropdown" 以切换下拉菜单，如下所示 -

<div class = "dropdown">
   <a data-toggle = "dropdown" href = "#">Dropdown trigger</a>
   
   <ul class = "dropdown-menu" role = "menu" aria-labelledby = "dLabel">
      ...
   </ul>
	
</div>

• 如果您需要保持链接完整（如果浏览器未启用 JavaScript 则很有用），请使用 data-target 属性代替 href = "#" -

<div class = "dropdown">
   <a id = "dLabel" role = "button" data-toggle = "dropdown" data-target = "#" href = "/page.html">
      Dropdown 
      <span class = "caret"></span>
   </a>
   
   <ul class = "dropdown-menu" role = "menu" aria-labelledby = "dLabel">
      ...
   </ul>
	
</div>

• 通过 JavaScript - 要通过 JavaScript 调用下拉菜单切换，请使用以下方法 -

$('.dropdown-toggle').dropdown()

示例

在导航栏内

以下示例演示了在导航栏内使用下拉菜单 -

<nav class = "navbar navbar-default" role = "navigation">

   <div class = "navbar-header">
      <a class = "navbar-brand" href = "#">TutorialsPoint</a>
   </div>
   
   <div>
      <ul class = "nav navbar-nav">
         <li class = "active"><a href = "#">iOS</a></li>
         <li><a href = "#">SVN</a></li>
         
         <li class = "dropdown">
            <a href = "#" class = "dropdown-toggle" data-toggle = "dropdown">
               Java 
               <b class="caret"></b>
            </a>
            
            <ul class = "dropdown-menu">
               <li><a href = "#">jmeter</a></li>
               <li><a href = "#">EJB</a></li>
               <li><a href = "#">Jasper Report</a></li>
               
               <li class = "divider"></li>
               <li><a href = "#">Separated link</a></li>
               
               <li class = "divider"></li>
               <li><a href = "#">One more separated link</a></li>
            </ul>
            
         </li>
      </ul>
   </div>
   
</nav>

在选项卡内

以下示例演示了在选项卡内使用下拉菜单 -

<p>Tabs With Dropdown Example</p>

<ul class = "nav nav-tabs">
   <li class = "active"><a href = "#">Home</a></li>
   <li><a href = "#">SVN</a></li>
   <li><a href = "#">iOS</a></li>
   <li><a href = "#">VB.Net</a></li>
   
   <li class = "dropdown">
      <a class = "dropdown-toggle" data-toggle = "dropdown" href = "#">
         Java 
         <span class = "caret"></span>
      </a>
      
      <ul class = "dropdown-menu">
         <li><a href = "#">Swing</a></li>
         <li><a href = "#">jMeter</a></li>
         <li><a href = "#">EJB</a></li>
         
         <li class = "divider"></li>
         <li><a href = "#">Separated link</a></li>
      </ul>
      
   </li>
	
   <li><a href = "#">PHP</a></li>
</ul>

选项

没有选项。

方法

下拉菜单切换有一个简单的方法来显示或隐藏下拉菜单。

$().dropdown('toggle')

示例

以下示例演示了下拉菜单插件方法的用法。

<nav class = "navbar navbar-default" role = "navigation">
   <div class = "navbar-header">
      <a class = "navbar-brand" href = "#">TutorialsPoint</a>
   </div>

   <div id = "myexample">
      <ul class = "nav navbar-nav">
         <li class = "active"><a href = "#">iOS</a></li>
         <li><a href = "#">SVN</a></li>
			
         <li class = "dropdown">
            <a href = "#" class = "dropdown-toggle">Java <b class = "caret"></b></a>
            
            <ul class = "dropdown-menu">
               <li><a id = "action-1" href = "#">jmeter</a></li>
               <li><a href = "#">EJB</a></li>
               <li><a href = "#">Jasper Report</a></li>
               
               <li class = "divider"></li>
               <li><a href = "#">Separated link</a></li>
               
               <li class = "divider"></li>
               <li><a href = "#">One more separated link</a></li>
            </ul>
            
         </li>
			
      </ul>
   </div>
   
</nav>

<script>
   $(function(){
      $(".dropdown-toggle").dropdown('toggle');
   }); 
</script>