Bootstrap 4下拉触发错误的项目答案

【问题标题】：Bootstrap 4 drop-down triggers wrong itemBootstrap 4下拉触发错误的项目
【发布时间】：2018-03-03 05:38:31
【问题描述】：

我正在开发一个导航栏，其中 2 个项目具有下拉菜单。第一个下拉菜单工作正常，但第二个总是触发第一个。在删除了我添加的任何额外样式后，我已经对其进行了测试，但它仍然无法正常工作。

我确定这很明显，但我似乎无法弄清楚。

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css">
<script src="https://code.jquery.com/jquery-3.1.0.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"></script>
<link href="css/app.css" rel="stylesheet" />

<!--  NAVIGATION BAR  -->
        <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
            <div class="container-fluid">
                <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarCollapsing" aria-controls="navbarCollapsing" aria-expanded="false" aria-label="Toggle navigation">
                    <span class="navbar-toggler-icon"></span>
                </button>
                <h1 class="navbar-brand mb-0">
                    <img class="pigs-logo" src="assets/logo.png">
                </h1>
                <div class="collapse navbar-collapse" id="navbarCollapsing">
                    <div class="nav navbar-nav">
                        <a class="nav-item nav-link active" href="./index.html">
                            Home
                        </a>
                        <a class="nav-item nav-link" href="./tour.html">
                            Tour
                        </a>
                        <a class="nav-item nav-link dropdown-toggle" href="#" id="navbar-media" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                            Media
                        </a>
                        <div class="dropdown">
                            <div class="dropdown-menu dropdown-menu-right" aria-labelledby="navbar-media">
                                <a class="dropdown-item" href="./videos.html">
                                    Videos
                                </a>
                                <a class="dropdown-item" href="./photos.html">
                                    Photos
                                </a>
                                <a class="dropdown-item" href="./audio.html">
                                    Audio
                                </a>
                            </div>
                        </div>
                        <a class="nav-item nav-link" href="./about.html">
                            About
                        </a>
                        <a class="nav-item nav-link dropdown-toggle" href="#" id="navbar-contact" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                            Contact
                        </a>
                        <div class="dropdown">
                            <div class="dropdown-menu dropdown-menu-right" aria-labelledby="navbar-contact">
                                <a class="dropdown-item" href="./contact.html">
                                    Contact
                                </a>
                                <a class="dropdown-item" href="./booking.html">
                                    Booking
                                </a>
                            </div>
                        </div>
                    </div>
                </div>
            </div>
        </nav>

【问题讨论】：

标签： html css bootstrap-4 dropdown

【解决方案1】：

就我而言，问题是我没有将整个下拉列表（触发元素和菜单项）包含在 <div class="dropdown"> 中。它仍然有效，直到我添加了第二个下拉菜单并发现它是由错误的元素触发的。

Bootstrap 4 下拉菜单应具有以下基本结构：

<div class="dropdown">
    <a href="#" data-toggle="dropdown">Triggering Element</a>
    <div class="dropdown-menu">
        <a href="#" class="dropdown-item">Item One</a>
        <a href="#" class="dropdown-item">Item Two</a>
        <a href="#" class="dropdown-item">Item Three</a>
    </div>

</div>

我错过了外部<div>。

【讨论】：

【解决方案2】：

请在导航栏中使用<li class="nav-item"><li>，不要直接使用a 标签。就像下面的代码。

<li class="nav-item">
  <a class="nav-link" href="#">Link</a>
</li>

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"></script>
<!--  NAVIGATION BAR  -->
       

<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
  <div class="container-fluid">
    <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarCollapsing" aria-controls="navbarCollapsing" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
    </button>
    <h1 class="navbar-brand mb-0">
      <img class="pigs-logo" src="assets/logo.png">
    </h1>
    <div class="collapse navbar-collapse" id="navbarCollapsing">
      <div class="nav navbar-nav">
        <li class="nav-item">
          <a class="nav-link active" href="./index.html">
          Home
          </a>
        <li>
        <li class="nav-item">
          <a class="nav-link" href="./tour.html">
          Tour
          </a>
        </li>
        <li class="nav-item">
          <a class="nav-link dropdown-toggle" href="#" id="navbar-media" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Media
          </a>
          <div class="dropdown">
            <div class="dropdown-menu dropdown-menu-right" aria-labelledby="navbar-media">
              <a class="dropdown-item" href="./videos.html">
              Videos
              </a>
              <a class="dropdown-item" href="./photos.html">
              Photos
              </a>
              <a class="dropdown-item" href="./audio.html">
              Audio
              </a>
            </div>
          </div>
        </li>
        <li class="nav-item">
          <a class="nav-link" href="./about.html">
          About
          </a>
        </li>
        <li class="nav-item">
          <a class="nav-item nav-link dropdown-toggle" href="#" id="navbar-contact" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Contact
          </a>
          <div class="dropdown">
            <div class="dropdown-menu dropdown-menu-right" aria-labelledby="navbar-contact">
              <a class="dropdown-item" href="./contact.html">
              Contact
              </a>
              <a class="dropdown-item" href="./booking.html">
              Booking
              </a>
            </div>
          </div>
        </li>
      </div>
    </div>
  </div>
</nav>

【讨论】：

非常欢迎...:) 如果回答有帮助，请接受。

【解决方案3】：

其他答案关于导航栏中下拉菜单的a标签的建议是错误的。

您当然可以像使用它们的方式一样使用纯粹的a 标签。

只有当涉及到多个下拉项时，当你有多个下拉项时，你需要将它们包装在一个div中类 btn-group 如下面的代码 sn-p 所示。（严格来说，第一个下拉菜单不需要这样包裹，但为了一致性我还是这样做了）

点击下方“运行代码sn-p”，展开全页进行现场测试：

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">

<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>

<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
    <div class="container-fluid">
        <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarCollapsing" aria-controls="navbarCollapsing" aria-expanded="false" aria-label="Toggle navigation">
            <span class="navbar-toggler-icon"></span>
        </button>
        <h1 class="navbar-brand mb-0">
            <img class="pigs-logo" src="https://placehold.it/30">
        </h1>
        <div class="collapse navbar-collapse" id="navbarCollapsing">
            <div class="nav navbar-nav">
                <a class="nav-item nav-link active" href="./index.html">
                    Home
                </a>
                <a class="nav-item nav-link" href="./tour.html">
                    Tour
                </a>
                <div class="btn-group">
                    <a class="nav-item nav-link dropdown-toggle" href="#" id="navbar-media" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                        Media
                    </a>
                    <div class="dropdown">
                        <div class="dropdown-menu dropdown-menu-right" aria-labelledby="navbar-media">
                            <a class="dropdown-item" href="./videos.html">
                                Videos
                            </a>
                            <a class="dropdown-item" href="./photos.html">
                                Photos
                            </a>
                            <a class="dropdown-item" href="./audio.html">
                                Audio
                            </a>
                        </div>
                    </div>
                </div>
                <a class="nav-item nav-link" href="./about.html">
                    About
                </a>
                <div class="btn-group">
                    <a class="nav-item nav-link dropdown-toggle" href="#" id="navbar-contact" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                        Contact
                    </a>
                    <div class="dropdown">
                        <div class="dropdown-menu dropdown-menu-right" aria-labelledby="navbar-contact">
                            <a class="dropdown-item" href="./contact.html">
                                Contact
                            </a>
                            <a class="dropdown-item" href="./booking.html">
                                Booking
                            </a>
                        </div>
                    </div>
                </div>
            </div>
        </div>
    </div>
</nav>

【讨论】：