jquery - Angular/Bootstrap - 导航栏显示不正确

Question

最近我在我的元素中添加了 Bootstrap 4、jQuery 和 Popper，但问题是当我呈现我的网页时，它显示了这样的导航栏(它位于一个名为 header 的组件中):

我还在我的 angular-cli.json 中添加了:

"styles": [
    "../node_modules/bootstrap/dist/css/bootstrap.min.css",
    "styles.css"
],
"scripts": [
    "../node_modules/jquery/dist/jquery.min.js",
    "../node_modules/popper.js/dist/umd/popper.min.js",
    "../node_modules/bootstrap/dist/js/bootstrap.min.js"
],

HTML 代码

<nav class="navbar navbar-light bg-light">
  <button class="navbar-toggler d-lg-none" type="button" data-toggle="collapse"
          data-target="#collapsibleNavId" aria-controls="collapsibleNavId"
          aria-expanded="false" aria-label="Toggle navigation"></button>
  <div class="collapse navbar-expand-md" id="collapsibleNavId">
    <a class="navbar-brand" href="#">My App/Logo with Text</a>
    <ul class="nav navbar-nav">
      <li class="nav-item active">
        <a class="nav-link" href="#">Nav 1 <span class="sr-only">(current)</span></a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">Nav 2</a>
      </li>
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="" id="dropdownId"
           data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Nav 3 dropdown</a>
        <div class="dropdown-menu" aria-labelledby="dropdownId">
          <a class="dropdown-item" href="#">Action 1</a>
          <a class="dropdown-item" href="#">Action 2</a>
        </div>
      </li>
    </ul>
    <form class="form-inline float-xs-right">
      <input class="form-control" type="text" placeholder="Search">
      <button class="btn btn-outline-success" type="submit">Search</button>
    </form>
  </div>
</nav>

Answer 1

您的导航栏中缺少一些类。查看以下代码以及其中使用的类和组件。如果您仍有疑问，请随时提问。但是该代码示例应该可以帮助您解决这个问题。

此外，d-lg-none 类说:“从大断点和断点以上隐藏它。这就是你想要的吗？这不是切换器设计的工作方式。Bootstrap 被设计mobile-first!这意味着切换器是默认设置。然后您使用 navbar-expand-lg 类，它基本上说:“隐藏切换器并将导航栏扩展到从 'lg' (=large) 断点开始水平。”

这是我的代码示例:

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

<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="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>

  <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <ul class="navbar-nav mr-auto">
      <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="#">Link</a>
      </li>
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Dropdown
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdown">
          <a class="dropdown-item" href="#">Action</a>
          <a class="dropdown-item" href="#">Another action</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="#">Something else here</a>
        </div>
      </li>
      <li class="nav-item">
        <a class="nav-link disabled" href="#">Disabled</a>
      </li>
    </ul>
    <form class="form-inline my-2 my-lg-0">
      <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
      <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
    </form>
  </div>
</nav>


<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>