Bootstrap升级3至4后，正常工作的Angular NavBar无法正常工作 [英] Working Angular NavBar not working after Bootstrap upgrade 3 to 4

问题描述

我有一个使用Bootstrap 3.3.7在Angular4中开发的简单工作的NavBar.当我尝试升级到Bootstrap 4(4.0.0-beta或4.0.0-alpha.6)时，NavBar根本不再显示在浏览器中(控制台中也没有显示错误).

I have a simple working NavBar developed in Angular4 with Bootstrap 3.3.7. When I try to upgrade to Bootstrap 4 (either 4.0.0-beta or 4.0.0-alpha.6) the NavBar is simply not displayed in the browser anymore (with no errors displayed in the console either).

HTML:

<nav class="navbar navbar-default">
  <div class="container-fluid">
    <div class="collapse navbar-collapse">
      <ul class="nav navbar-nav">
        <li routerLinkActive="active current"><a routerLink="/messages"><b>Messages</b></a></li>
        <li routerLinkActive="active current"><a routerLink="/transformations"><b>Transformations</b></a></li>
        <li routerLinkActive="active current"><a routerLink="/actions"><b>Actions</b></a></li>
        <li routerLinkActive="active current"><a routerLink="/rules"><b>Rules</b></a></li>
      </ul>
    </div>
  </div>
</nav>

打字稿:

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'navbar',
  templateUrl: './navbar.component.html',
  styleUrls: ['./navbar.component.css']
})
export class NavbarComponent implements OnInit {

  constructor() { }

  ngOnInit() {
  }

}

任何帮助都非常感谢，马丁，

Any help greatly appreciated, thanks, Martin

推荐答案

您的导航栏未显示的原因是Bootstrap 4几乎是Bootstrap 3的完全重写.两个版本是完全不兼容的.

The reason why your navbar is not displaying is because Bootstrap 4 is almost a complete rewrite of Bootstrap 3. In other words, the two versions are completely incompatible.

这是Bootstrap 4中基本导航栏结构和组件的示例:

Here's an example of a basic navbar structure and components in Bootstrap 4:

<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>

还要注意下面的各种JavaScript组件.这些对于使导航栏正常运行至关重要.确保加载它们.以此顺序.

Also notice the various JavaScript components below. Those are essential to make the navbar work. Make sure you load them. In that order.

对于您的特定导航栏，HTML如下:

For your specific navbar the HTML would be this:

<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">
   <div class="container">
       <a class="navbar-brand" href="#">NavbarBrand</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" routerLinkActive="active current">
                   <a class="nav-link" routerLink="/messages"><b>Messages</b></a>
               </li>
               <li class="nav-item" routerLinkActive="active current">
                   <a class="nav-link" routerLink="/transformations"><b>Transformations</b></a>
               </li>
               <li class="nav-item" routerLinkActive="active current">
                   <a class="nav-link" routerLink="/actions"><b>Actions</b></a>
               </li>
               <li class="nav-item" routerLinkActive="active current">
                   <a class="nav-link" routerLink="/rules"><b>Rules</b></a>
               </li>
           </ul>
       </div>
   </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>

P.S.您应该避免对导航栏使用container-fluid类，因为宽屏4K屏幕上的用户会生气.改用container(如我的上一片段所示).

P.S. You should avoid using the container-fluid class for navbars because users on wide 4K screens will be mad at you. Use container instead (as shown in my last snippet).

这篇关于Bootstrap升级3至4后，正常工作的Angular NavBar无法正常工作的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！