导航栏中的下拉切换问题，使用ng-bootstrap（4）angular 2（cli）

Question

我按照here描述的说明和css完美地工作。对于下拉切换，我使用了此代码

<nav class="navbar navbar-light bg-faded">
  <a class="navbar-brand" href="#">Navbar</a>
  <ul class="nav 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="#">Link</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="supportedContentDropdown" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Dropdown</a>
      <div class="dropdown-menu" aria-labelledby="supportedContentDropdown">
        <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>
  <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>
</nav>

但是下拉切换不起作用，尽管我为Root添加了NgbModule。请知道我是否必须在我的组件提供程序数组或其他任何内容中包含其他内容。提前致谢

Answer 1

我得到它像这样工作：

<nav class="navbar navbar-light bg-faded">
  <a class="navbar-brand" href="#">Navbar</a>
  <ul class="nav 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="#">Link</a>
    </li>
    <li class="nav-item">
      <a class="nav-link" href="#">Link</a>
    </li>
    <li class="nav-item dropdown">
      <div ngbDropdown class="d-inline-block">
        <button class="btn btn-outline-primary" id="dropdownMenu1" ngbDropdownToggle>Toggle dropdown</button>
        <div ngbDropdownMenu class="dropdown-menu" aria-labelledby="dropdownMenu1">
          <button class="dropdown-item">Action - 1</button>
          <button class="dropdown-item">Another Action</button>
          <button class="dropdown-item">Something else is here</button>
        </div>
      </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>
</nav>

如评论中所述（link）

Answer 2

我最终做了这样的事情：

在html模板中我有这个代码：

 <nav id="mainNavbar" class="navbar navbar-expand-lg navbar-dark bg-dark fixed-top">
        <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
           (click)="toggleCollapsed()">
          <span class="navbar-toggler-icon"></span>
        </button>
        <div id="navbarSupportedContent" [ngClass]="{'collapse': collapsed, 'navbar-collapse': true}">
......
</nav>

在组件我有这个

 export class NavComponent {
      collapsed = true;
      toggleCollapsed(): void {
        this.collapsed = !this.collapsed;
      }
 }

Answer 3

修改你的淹没html部分到这个：

<li class="nav-item dropdown">
  <div ngbDropdown class="d-inline-block">
    <button class="btn btn-outline-primary" id="dropdownMenu1" 
      **ngbDropdownToggle**>use Attrib ngbDropdownToggle</button>

    <!-- use  ngbDropdownMenu -->
    <div **ngbDropdownMenu** class="dropdown-menu" aria-labelledby="dropdownMenu1">
      <button class="dropdown-item">Action - 1</button>
      <button class="dropdown-item">Another Action</button>
      <button class="dropdown-item">Something else is here</button>
    </div>
  </div>
</li>