[翻译]  Bootstrap 4 Dropdown Menu not working?

[CHINESE]  Bootstrap 4下拉菜单不起作用?


I copied the official Bootstrap 4 example for dropdown menus but it is not working, that is nothing is dropped down.

我为下拉菜单复制了官方的Bootstrap 4示例,但它没有工作,没有任何内容被删除。

<li class="nav-item dropdown">
    <a class="nav-link dropdown-toggle" href="#" id="dropdown01" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dropdown</a>
    <div class="dropdown-menu" aria-labelledby="dropdown01">
    <a class="dropdown-item" href="#">Action</a>
    <a class="dropdown-item" href="#">Another action</a>
    <a class="dropdown-item" href="#">Something else here</a>
  </div>
</li>

5 个解决方案

#1


23  

Edit: In case anyone else is having this problem, I believe the solution for OP was that he had not imported popper.js.

编辑:如果其他人遇到这个问题,我相信OP的解决方案是他没有导入popper.js。

Check that jQuery and all the relevant Bootstrap components are there. Also check the console and make sure there are no errors.

检查jQuery和所有相关的Bootstrap组件是否存在。还要检查控制台并确保没有错误。

<!DOCTYPE html>
<html lang="en">
<head>
  <!-- Required meta tags -->
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

  <!-- Bootstrap CSS -->
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/css/bootstrap.min.css" integrity="sha384-/Y6pD6FV/Vv2HJnA6t+vslU6fwYXjCFtcEpHbNJ0lyAFsXTsjBbfaDjzALeQsN6M" crossorigin="anonymous">
</head>
<body>
  <nav class="navbar navbar-expand-lg navbar-light bg-light">
    <a class="navbar-brand" href="#">Navbar</a>
      <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNavDropdown" aria-controls="navbarNavDropdown" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="navbarNavDropdown">
      <ul class="navbar-nav">
        <li class="nav-item active">
          <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Features</a>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="#">Pricing</a>
        </li>
        <li class="nav-item dropdown">
          <a class="nav-link dropdown-toggle" href="http://example.com" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
        Dropdown link
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
          <a class="dropdown-item" href="#">Action</a>
          <a class="dropdown-item" href="#">Another action</a>
          <a class="dropdown-item" href="#">Something else here</a>
        </div>
        </li>
      </ul>
    </div>
  </nav>

  <!-- Optional JavaScript -->
  <!-- jQuery first, then Popper.js, then Bootstrap JS -->
  <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.11.0/umd/popper.min.js" integrity="sha384-b/U6ypiBEHpOf/4+1nzFpr53nxSS+GLCkfwBdFNTxtclqqenISfwAzpKaMNFNmj4" crossorigin="anonymous"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/js/bootstrap.min.js" integrity="sha384-h0AbiXch4ZDo7tp9hKZ4TsHbi047NrKGLO3SEJAg45jXxnGIfYzk4Si90RDIqNm1" crossorigin="anonymous"></script>
</body>
</html>

#2


4  

try to add these lines at the end of the file

尝试在文件末尾添加这些行

<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</body>
</html>

#3


1  

Make sure to include the Bootstrap CSS either via the Bootstrap CDN or download it and link it locally

确保通过Bootstrap CDN包含Bootstrap CSS或下载并在本地链接它

#4


1  

It's an issue with popper.js file. What I found at the official site was that bundle files include popper in itself but not jquery. I managed to fix it by adding link to these files:

这是popper.js文件的一个问题。我在官方网站上发现的是捆绑文件本身包含popper但不包括jquery。我设法通过添加这些文件的链接来修复它:

bootstrap.bundle.js
bootstrap.bundle.min.js

bootstrap.bundle.js bootstrap.bundle.min.js

I removed popper.js however since it comes within the bundle file.

我删除了popper.js,因为它在bundle文件中。

#5


1  

Assuming Bootstrap and Popper libraries were installed using Nuget package manager, for a web application using Visual Studio, in the Master page file (Site.Master), right below where body tag begins, include the reference to popper.min.js by typing:

假设使用Nuget包管理器安装Bootstrap和Popper库,对于使用Visual Studio的Web应用程序,在主页面文件(Site.Master)中,在body标签开始的正下方,通过键入以下内容包括对popper.min.js的引用:

<script src="Scripts/umd/popper.min.js"></script>

Here is an image to better display the location:

这是一张更好地显示位置的图片:

enter image description here

Notice the reference of the popper library to be added should be the one inside umd folder and not the one outside on Scripts folder.

请注意,要添加的popper库的引用应该是umd文件夹中的一个,而不是Scripts文件夹外的文件夹。

This should fix the problem.

这应该可以解决问题。


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