无法弄清楚如何使这个导航选项卡成为下拉菜单

Question

我只是没弄清楚语法我试图在单击第二个按钮时出现下拉菜单。

<!DOCTYPE html>
<head>

  <meta charset="utf-8" />
  <meta http-equiv="X-UA-Compatible" content="IE=edge" />
  <meta name="viewport" content="width=device-width, initial-scale=1" />
  <link rel="stylesheet" href=
  "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity=
  "sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin=
  "anonymous" type="text/css" />

  <!-- Font Awesome  -->

  <script src="https://use.fontawesome.com/926120954b.js" type="text/javascript">
</script>

<!-- My CSS  -->
<link rel="stylesheet" type="text/css" href="mystyle.css">


</head>

<body>


<ul class="nav nav-tabs">
  <li role="presentation"><a href="#"><i class="fa fa-home fa-1g" aria-hidden="true"></i></a></li>

<!-- ****BEGIN THE DROPDOWN TAB-->

<li role="Presentation" class="dropdown-menu">
    <a class="Pet" data-toggle="dropdown" href="#" role="button" aria-haspopup="true" aria-expanded="false">
     Community <span class="caret"></span>
    </a>
    <ul class="dropdown-menu">
      <li>item</li>
    </ul>
  </li>




<!-- ***END  THE DROPDOWN TAB  -->


  <li role="presentation"><a href="#">Pet Help</a></li>
  <li role="presentation"><a href="#">Pets for Sale</a></li>
  <li role="presentation"><a href="#">Pet Services</a></li>

</ul>








 <!-- jQuery (necessary for Bootstrap's JavaScript plugins) -->
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js" type=
  "text/javascript">
</script>
</body>
</html>

我第一次尝试制作导航菜单。（由于某些原因，我无法在不提供 "details" 的情况下提交此问题，因此请原谅此处无意义的文字）

Answer 1

我认为您错过了对汉堡包导航所需的 bootstrap 的 javascript 库的调用。在添加 jquery 引用（即 <script src="...jquery.min.js"...）

后尝试添加此内容

<!-- Latest compiled and minified JavaScript -->
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>

有关详细信息，请参阅 Bootstrap 文档页面：Getting Started，以及下面更新的代码片段。

<link rel="stylesheet" href= "https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity=
  "sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin=
  "anonymous" type="text/css" />

  <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js" type=
  "text/javascript">
</script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>

  <!-- Font Awesome  -->
  <script src="https://use.fontawesome.com/926120954b.js" type="text/javascript">
</script>

<!-- My CSS  -- >
<link rel="stylesheet" type="text/css" href="mystyle.css">-->
<!--end head: </head>  start body:<body>-->

<ul class="nav nav-tabs">
  <li role="presentation"><a href="#"><i class="fa fa-home fa-1g" aria-hidden="true"></i></a></li>

<!-- ****BEGIN THE DROPDOWN TAB-->

<li role="Presentation" class="dropdown-menu">
    <a class="Pet" data-toggle="dropdown" href="#" role="button" aria-haspopup="true" aria-expanded="false">
     Community <span class="caret"></span>
    </a>
    <ul class="dropdown-menu">
      <li>item</li>
    </ul>
  </li>

<!-- ***END  THE DROPDOWN TAB  -->
  <li role="presentation"><a href="#">Pet Help</a></li>
  <li role="presentation"><a href="#">Pets for Sale</a></li>
  <li role="presentation"><a href="#">Pet Services</a></li>

</ul>

无法弄清楚如何使这个导航选项卡成为下拉菜单

Cant figure out how to make this nav tab a dropdown menu

html

nav

twitter-bootstrap