Angular 4引导alpha导航栏未正确渲染

我正在尝试将引导4添加到Angular 4应用程序中。我跟在后面。但是导航栏工作不正常

我按照以下步骤安装引导程序

首先，我使用以下npm命令安装了引导程序

npm install bootstrap@next --save

我可以在node_modules文件夹中看到引导文件夹

然后我将引导css路径包含在全局css文件中

/* You can add global styles to this file, and also import other style files */
@import "~bootstrap/dist/css/bootstrap.css";

body {
    padding-top: 5rem;
}
.starter-template {
    padding: 3rem 1.5rem;
    text-align: center;
}

然后我打开index.html文件，并在文件末尾添加了JQuery和其他JS文件

<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/js/bootstrap.min.js" integrity="sha384-h0AbiXch4ZDo7tp9hKZ4TsHbi047NrKGLO3SEJAg45jXxnGIfYzk4Si90RDIqNm1" crossorigin="anonymous"></script>
<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/1.11.0/umd/popper.min.js" integrity="sha384-b/U6ypiBEHpOf/4+1nzFpr53nxSS+GLCkfwBdFNTxtclqqenISfwAzpKaMNFNmj4" crossorigin="anonymous"></script>

我确实运行了服务器，它加载了引导CSS。但导航栏渲染不正确。我进行了硬重新加载以清除缓存

我的app.component.html文件是

<div class="container">

  <div class="starter-template">
    <h1>Bootstrap starter template</h1>
    <p class="lead">Use this document as a way to quickly start any new project.<br> All you get is this text and a mostly barebones HTML document.</p>
  </div>

</div><!-- /.container -->

引导启动程序模板
将此文档用作快速启动任何新项目的一种方式。
您得到的只是此文本和一个基本上没有内容的HTML文档

app-navbar.componenet.html文件

<nav class="navbar">
  <div class="container">
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand" href="#">Project name</a>
    </div>
    <div id="navbar" class="collapse navbar-collapse">
      <ul class="nav navbar-nav">
        <li class="active"><a href="#">Home</a></li>
        <li><a href="#about">About</a></li>
        <li><a href="#contact">Contact</a></li>
      </ul>
    </div><!--/.nav-collapse -->
  </div>
</nav>

切换导航

控制台显示引导CSS和JS文件加载正确

---

从图像上看，您似乎安装了最新版本的bootstrap 4，它是beta版，但您的代码是针对alpha的，请尝试此操作，它应该可以工作：

<nav class="navbar navbar-expand-lg navbar-light bg-light">
        <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>
        <a class="navbar-brand" href="#">Project name</a>

        <div id="navbar" class="collapse navbar-collapse">
            <ul class="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="#">About </a>
                </li>
                <li class="nav-item">
                    <a class="nav-link" href="#">Contact </a>
                </li>
            </ul>
        </div>
        <!--/.nav-collapse -->
    </nav>

---

从图像上看，您似乎安装了最新版本的bootstrap 4，它是beta版，但您的代码是针对alpha的，请尝试此操作，它应该可以工作：

<nav class="navbar navbar-expand-lg navbar-light bg-light">
        <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>
        <a class="navbar-brand" href="#">Project name</a>

        <div id="navbar" class="collapse navbar-collapse">
            <ul class="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="#">About </a>
                </li>
                <li class="nav-item">
                    <a class="nav-link" href="#">Contact </a>
                </li>
            </ul>
        </div>
        <!--/.nav-collapse -->
    </nav>

---

您需要将引导版本降级为alpha或使用beta代码示例您需要将引导版本降级为alpha或使用beta代码示例谢谢！我在你的代码中为导航元素添加了固定的顶级类，并解决了这个问题。谢谢！我在代码中为nav元素添加了fixed top类，解决了这个问题。