Question

这是我的HTML代码，具有引导程序类，并在Angular中使用，此处dropdown不会扩展，值保存数据和提取数据未显示在浏览器中。但是，如果我在任何在线引导工作区中使用相同的代码，它就可以正常工作（例如W3schools）。这里有些东西不支持它。我不明白我在这里想念的是什么。谁能帮我解决这个问题？

<ul class="nav navbar-nav navbar-right">
        <li class="dropdown open">
           <a  class="dropdown-toggle" role="button"  href="#">Manage <span class="caret"></span></a>
            <ul class="dropdown-menu">
              <li > <a href="#"> Save Data</a></li>
              <li> <a href="#"> Fetch Data</a></li>
             </ul>
          </li>
     </ul>

我已经在文件angular.json文件中添加了Bootstrap CSS，如下所示，

 "styles": [
              "src/styles.css",
              "node_modules/bootstrap/dist/css/bootstrap.min.css"
            ],

我正在使用Bootstrap v4.1.2。

Answer 1

您想制作一个header.component.html文件，在其中可以放置徽标和nav链接，其中包括 Manage ， 保存数据 和 获取数据 ...我认为您要完成的工作是这样的：

 <nav class="navbar navbar-default">
  <div class="container-fluid">
    <div class="navbar-header">
      <a routerLink="/" class="navbar-brand">Your App Name</a>
    </div>

    <div class="navbar-default">
      <ul class="nav navbar-nav">
        <li routerLinkActive="active">
          <a routerLink="/recipes">Recipes</a>
        </li>
        <li routerLinkActive="active">
          <a routerLink="/shopping-list">Shopping List</a>
        </li>
      </ul>
      <ul class="nav navbar-nav navbar-right">
        <ng-template [ngIf]="!authService.isAuthenticated()">
          <li><a routerLink="/signin">Sign In</a></li>
          <li><a routerLink="/signup">Sign Up</a></li>
        </ng-template>
          <li *ngIf="authService.isAuthenticated()"><a style="cursor: pointer;" (click)="onLogout()">Sign Out</a></li>
        <li appDropdown class="dropdown" *ngIf="authService.isAuthenticated()">
          <a class="dropdown-toggle" role="button" style="cursor: pointer;">Manage <span class="caret"></span></a>
          <ul class="dropdown-menu">
            <li><a style="cursor: pointer;" (click)="onSaveData()">Save Data</a></li>
            <li><a style="cursor: pointer;" (click)="onFetchData()">Fetch Data</a></li>
          </ul>
        </li>
      </ul>
    </div>
  </div>
</nav>

在此代码下，您可以找到一个简单的 Bootstrap 4 实现：

<!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/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">

    <title>Simple Example!</title>
  </head>
  <body>
<!-- Large button groups (default and split) -->
<div class="btn-group">
  <button class="btn btn-success btn-lg dropdown-toggle" type="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Save Data
  </button>
  <div class="dropdown-menu">
    ...
  </div>
</div>
<div class="btn-group">
  <button class="btn btn-info btn-lg dropdown-toggle" type="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
    Fetch Data
  </button>
  <div class="dropdown-menu">
    ...
  </div>
</div>


    <!-- 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/1.12.9/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>

Bootstrap下拉列表没有扩展

1 个答案: