我使用引导程序创建了一个简单的导航栏，但是当我单击它时，它不显示列表项，它在更大的屏幕上工作正常。 我尝试了很多替代方案，但都不起作用。
<html>
<head>
<meta charset = "utf8">
<meta http-equiv = "X-UA-Compatible" content = "IE = edge">
<meta name = "viewport" content = "width = device-width initial-scale = 1">
<link rel = "stylesheet" type = "text/css" href = "conFusion/css/bootstrap.min.css">
<link rel = "stylesheet" type = "text/css" href = "conFusion/css/bootstrap-theme.min.css">
</head>
<body>
<nav class = "navbar navbar-inverse" role = "navigation">
<div class = "container">
<div class = "navbar-header">
<button type = "button" class = "navbar-toggle collapsed"
data-toggle = "collapse" data-target = "#navbar" area-controls = "navbar"
aria-expanded="false">
<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">Indore Medical</a>
</div>
<div id = "navbar" class = "navbar-collapse collapse">
<ul class = "nav navbar-nav">
<li class = "active"><a href = "#">Main-Course</a></li>
<li><a href = "#">Starters</a></li>
<li><a href = "#">Desert</a></li>
<li><a href = "#">About-us</a></li>
</ul>
</div>
</div>
</nav>
</body>
</html>
考虑到您提供的代码，似乎您尚未包含 jQuery 库文件，并且 Bootstrap 的 JavaScript 需要 jQuery 来运行其 JS/jQ 事件，例如 toggle menu 等。
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>
<nav class="navbar navbar-inverse" role="navigation">
<div class="container">
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" area-controls="navbar" aria-expanded="false">
<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">Indore Medical</a>
</div>
<div id="navbar" class="navbar-collapse collapse">
<ul class="nav navbar-nav">
<li class="active"><a href="#">Main-Course</a>
</li>
<li><a href="#">Starters</a>
</li>
<li><a href="#">Desert</a>
</li>
<li><a href="#">About-us</a>
</li>
</ul>
</div>
</div>
</nav>包含 Bootstrap javascript 文件。如果您已经包含 bootstrap.bundle.min.js（其中包含 Bootstrap 的 JavaScript 和必要的 Bootstrap JavaScript 插件），则无需单独包含 bootstrap.min.js。 bootstrap.bundle.min.js 包含 Bootstrap 组件和 JavaScript 功能所需的一切，包括导航栏切换器功能。