下拉菜单不会使用引导程序出现

Question

我正在尝试使用引导程序创建pulldown menu。 但由于某种原因，pulldown menu未出现。 我不理解这个概念还是它是一个错字？

<div class="container"> 
<a href="index.php" title="Homepage"> 
<button type="button" class="btn btn-default sm active"> 
<span class="glyphicon glyphicon-home"> Home</button></a> 

<a href="about.php" title="About"> 
<button type="button" class="btn btn-default sm"> 
    <span class="glyphicon glyphicon-briefcase"> About</button></a> 
<div class="btn-group"> 
<button type="button" class="btn btn-default sm data-toggle="dropdown"> 
    <span class="glyphicon glyphicon-eye-open"> My Dropdown</button> 
    <ul class="dropdown-menu" role="menu"> 
     <li><a href="drop1.php">Dropdown 1</a></li> 
     <li><a href="droop2.php">Dropdown 2</a></li> 
    </ul> 
</div> 
</div> 

Answer 1

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css" rel="stylesheet"> 
 
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.4/jquery.min.js"></script> 
 
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script> 
 
<div class="container"> 
 
     <a href="index.php" title="Homepage"> 
 
      <button type="button" class="btn btn-default sm active"> 
 
      <span class="glyphicon glyphicon-home"> Home</button> 
 
     </a> 
 

 
     <a href="about.php" title="About"><button type="button" class="btn btn-default sm"><span class="glyphicon glyphicon-briefcase"> About</button></a> 
 
     <div class="btn-group"> 
 
      <button type="button" class="btn btn-default sm" data-toggle="dropdown"><span class="glyphicon glyphicon-eye-open"> My Dropdown</button> 
 
      <ul class="dropdown-menu" role="menu"> 
 
       <li><a href="drop1.php">Dropdown 1</a></li> 
 
       <li><a href="droop2.php">Dropdown 2</a></li> 
 
      </ul> 
 
     </div> 
 
    </div>

您的代码 <button type="button" class="btn btn-default sm data-toggle="dropdown">

你错过了"。

正确 <button type="button" class="btn btn-default sm" data-toggle="dropdown">