Bootstrap导航栏切换按钮不起作用[重复]答案

【问题标题】：Bootstrap Navbar Toggle Button Does Not Work [duplicate]Bootstrap导航栏切换按钮不起作用[重复]
【发布时间】：2018-09-12 17:25:19
【问题描述】：

我刚刚创建了一个新文件，并从其官方网站复制并粘贴了 Bootstrap 起始代码。

但问题是，每当我最小化浏览器屏幕以测试此菜单在小型设备中的工作方式时，菜单切换按钮似乎不起作用。

如图所示，当我单击按钮时，它不会折叠并以某种方式显示菜单项：

那么这个菜单有什么问题呢？

代码：

    <!doctype html>
<html lang="en">
    <head>
        <!-- Required meta tags -->
        <meta charset="utf-8">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <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>Hello, world!</title>
    </head>
    <body>
        <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 topMenu" 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>  
    </body>
</html>

【问题讨论】：

请重新加载页面
你没有 jquery、bootstrap.js 和 popper.js。代码工作正常：codeply.com/go/FVVO057KLm

标签： html css twitter-bootstrap responsive-design responsive

【解决方案1】：

试试这个代码 - 如果你发布你的代码，那么我可以看到你在做什么。你肯定有 class="navigation-toggle" 和 data-toggle="collapse" 和 data-target="#navigation-id" （链接到你的导航菜单 - 这需要完成以同步两者。

Use the CDN 
<head>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
        <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>

</head>

<header class="navigation navbar" role="navigation">
    <div class="container-fluid">
        <div class="row">

               <header class="navigation navbar" role="navigation">
    <div class="container-fluid">
        <div class="row">

                <div class="col-sm-4">                 
                    <img class="navbar-brand contini-logo" src="contini-logo.jpg">
                </div>

                <nav class="col-sm-8"> 
                    <div class="row">
                        <div class="col-sm-12">
                            <div class="navbar-header">
                                <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="contini-navigation">
                                    <span class="sr-only">Toggle Navigation</span>
                                    <span class="icon-bar"></span>
                                    <span class="icon-bar"></span>
                                    <span class="icon-bar"></span>
                                </button>
                            </div> <!--Navbar header end - wierd since it is a wrapper -->

                            <div class="collapse navbar-collapse" id="contini-navigation">
                                <ul class="nav navbar-nav" id="main-menu">
                                    <li><a>Home</a></li>  
                                    <li class="dropdown"><a class="dropdown-toggle" data-toggle="dropdown">Our Restaurants<span class="caret"></span></a>
                                        <ul class="dropdown-menu">
                                            <li>Contini George Street</li>
                                            <li>Canonball Restaurant & Bar</li>
                                            <li>The Scottish Cafe</li>
                                        </ul>    
                                        </li> 
                                    <li><a>About</a></li> 
                                    <li><a>Events</a></li>    
                                    <li><a>What's On</a></li> 
                                    <li><a>News</a></li> 
                                    <li><a>Gifts</a></li> 
                                </ul>
                            </div> <!-- id contini navigation -->
                        </div>  <!-- col-sm-12 -->  
                    </div>   <!-- row --> 
                   <!--  <div class="row">   ===== DON"T Understand what they have done on the original site here =====
                        <div class="col-sm-12">
                         </div>
                    </div>  -->       

                </nav>
        </div> <!-- row -->
    </div>  <!-- container -->
 </header>

【讨论】：

当我点击切换按钮时，菜单突然出现然后消失！
这段代码是 Bootstrap 3，不是 Bootstrap 4。