为什么 Bootstrap 不起作用？

Question

我是bootstrap的新人，所以无法正确显示导航

<!DOCTYPE html>
<html>
<head>
  <title>Title</title>
   <meta name="viewport" content="width=device-width, initial-scale=1">
    <link  href="./bower_components/bootstrap/dist/css/bootstrap.min.css" rel="stylesheet"/>
    <script src="./bower_components/jquery/dist/jquery.min.js"></script>
    <script src="./bower_components/bootstrap/dist/js/bootstrap.min.js"></script>
</head>
<body>
   <nav class="navbar navbar-toggleable-md navbar-light bg-faded">
    <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarTogglerDemo02" aria-controls="navbarTogglerDemo02" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <a class="navbar-brand" href="#">Navbar</a>

    <div class="collapse navbar-collapse" id="navbarTogglerDemo02">
      <ul class="navbar-nav mr-auto mt-2 mt-md-0">
        <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 disabled" href="#">Disabled</a>
        </li>
      </ul>
      <form class="form-inline my-2 my-lg-0">
        <input class="form-control mr-sm-2" type="text" placeholder="Search">
        <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
      </form>
    </div>
  </nav>
    <button class="btn btn-success">Botón Verde</button>
</body>
</html>

我使用 bower 安装了 jquery 和 bootstrap。这是它的显示方式： https://ibb.co/bXhUdv

Answer 1

根据评论编辑：

To install boostrap 4 alpha 6 through bower do:

bower install bootstrap#v4.0.0-alpha.6

原回答：

可能与 bower 有关，你确定你正在加载 bootstrap 4 alpha 6 而不是 bootstrap 3 吗？ Fiddle 上的代码似乎没问题，见下文：

尝试从 CDN 手动加载它，看看是否可以将问题隔离到 bower
还可以考虑在 </body> 结束标记之前加载各自订单中的所有 JS 文件。

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.3.7/js/tether.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"></script>
<nav class="navbar navbar-toggleable-md navbar-light bg-faded">
  <button class="navbar-toggler navbar-toggler-right" type="button" data-toggle="collapse" data-target="#navbarTogglerDemo02" aria-controls="navbarTogglerDemo02" aria-expanded="false" aria-label="Toggle navigation">
     <span class="navbar-toggler-icon"></span>
  </button>
  <a class="navbar-brand" href="#">Navbar</a>
  <div class="collapse navbar-collapse" id="navbarTogglerDemo02">
    <ul class="navbar-nav mr-auto mt-2 mt-md-0">
      <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 disabled" href="#">Disabled</a>
      </li>
    </ul>
    <form class="form-inline my-2 my-lg-0">
      <input class="form-control mr-sm-2" type="text" placeholder="Search">
      <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
    </form>
  </div>
</nav>
<button class="btn btn-success">Botón Verde</button>

为什么 Bootstrap 不起作用？

Why Bootstrap is not working?

css

jquery

bootstrap-4