Jquery 具有多个分割导航的引导4导航栏'；t崩溃
在此版本中，平板电脑菜单中仅显示第一个菜单项。添加样式显示时：flex；对于#navbarsExampleDefault，它会显示其他项目，但我无法折叠/隐藏菜单项。添加可见性：隐藏；只隐藏菜单项，但占用相同的空间。我只包括了一个菜单项以保持简短Jquery 具有多个分割导航的引导4导航栏'；t崩溃,jquery,twitter-bootstrap,bootstrap-4,navbar,hamburger-menu,Jquery,Twitter Bootstrap,Bootstrap 4,Navbar,Hamburger Menu,在此版本中，平板电脑菜单中仅显示第一个菜单项。添加样式显示时：flex；对于#navbarsExampleDefault，它会显示其他项目，但我无法折叠/隐藏菜单项。添加可见性：隐藏；只隐藏菜单项，但占用相同的空间。我只包括了一个菜单项以保持简短 <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"&
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="icon" href="#">
<title>Home</title>
<!--BOOTSTRAP-->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="css/style.css">
<link href="https://fonts.googleapis.com/css?family=Roboto+Condensed:300,300i,400,400i|Roboto:300,300i,400,400i" rel="stylesheet">
<button class="btn btn-link navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 30 30" width="30" height="30" focusable="false"><title>Menu</title><path stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-miterlimit="10" d="M4 7h22M4 15h22M4 23h22"></path></svg>
</button>
<!-- SPLIT NAVBARS -->
<div class="btn-group navbar-collapse collapse" id="navbarsExampleDefault">
<button type="button" class="btn" id="button-1"><a href="csr-lfg.html">CSR at LF</a></button>
<button type="button" class="btn dropdown-toggle dropdown-toggle-split" id="button-1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<span class="sr-only">Toggle Dropdown</span>
</button>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Submenu Item 1</a>
<a class="dropdown-item" href="#">Submenu Item 2</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Submenu Item 3</a>
<a class="dropdown-item" href="#">Submenu Item 4</a>
<a class="dropdown-item" href="#">Submenu Item 5</a>
<a class="dropdown-item" href="#">Submenu Item 6</a>
</div>
</div>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="icon" href="#">
<title>Home</title>
<!--BOOTSTRAP-->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="css/style.css">
<link href="https://fonts.googleapis.com/css?family=Roboto+Condensed:300,300i,400,400i|Roboto:300,300i,400,400i" rel="stylesheet">
<button class="btn btn-link navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 30 30" width="30" height="30" focusable="false"><title>Menu</title><path stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-miterlimit="10" d="M4 7h22M4 15h22M4 23h22"></path></svg>
</button>
<!-- SPLIT NAVBARS -->
<div class="btn-group navbar-collapse collapse" id="navbarsExampleDefault">
<button type="button" class="btn" id="button-1"><a href="csr-lfg.html">CSR at LF</a></button>
<button type="button" class="btn dropdown-toggle dropdown-toggle-split" id="button-1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<span class="sr-only">Toggle Dropdown</span>
</button>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Submenu Item 1</a>
<a class="dropdown-item" href="#">Submenu Item 2</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Submenu Item 3</a>
<a class="dropdown-item" href="#">Submenu Item 4</a>
<a class="dropdown-item" href="#">Submenu Item 5</a>
<a class="dropdown-item" href="#">Submenu Item 6</a>
</div>
</div>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="icon" href="#">
<title>Home</title>
<!--BOOTSTRAP-->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="css/style.css">
<link href="https://fonts.googleapis.com/css?family=Roboto+Condensed:300,300i,400,400i|Roboto:300,300i,400,400i" rel="stylesheet">
<button class="btn btn-link navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 30 30" width="30" height="30" focusable="false"><title>Menu</title><path stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-miterlimit="10" d="M4 7h22M4 15h22M4 23h22"></path></svg>
</button>
<!-- SPLIT NAVBARS -->
<div class="btn-group navbar-collapse collapse" id="navbarsExampleDefault">
<button type="button" class="btn" id="button-1"><a href="csr-lfg.html">CSR at LF</a></button>
<button type="button" class="btn dropdown-toggle dropdown-toggle-split" id="button-1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<span class="sr-only">Toggle Dropdown</span>
</button>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Submenu Item 1</a>
<a class="dropdown-item" href="#">Submenu Item 2</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Submenu Item 3</a>
<a class="dropdown-item" href="#">Submenu Item 4</a>
<a class="dropdown-item" href="#">Submenu Item 5</a>
<a class="dropdown-item" href="#">Submenu Item 6</a>
</div>
</div>
家
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="icon" href="#">
<title>Home</title>
<!--BOOTSTRAP-->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="css/style.css">
<link href="https://fonts.googleapis.com/css?family=Roboto+Condensed:300,300i,400,400i|Roboto:300,300i,400,400i" rel="stylesheet">
<button class="btn btn-link navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 30 30" width="30" height="30" focusable="false"><title>Menu</title><path stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-miterlimit="10" d="M4 7h22M4 15h22M4 23h22"></path></svg>
</button>
<!-- SPLIT NAVBARS -->
<div class="btn-group navbar-collapse collapse" id="navbarsExampleDefault">
<button type="button" class="btn" id="button-1"><a href="csr-lfg.html">CSR at LF</a></button>
<button type="button" class="btn dropdown-toggle dropdown-toggle-split" id="button-1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<span class="sr-only">Toggle Dropdown</span>
</button>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Submenu Item 1</a>
<a class="dropdown-item" href="#">Submenu Item 2</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Submenu Item 3</a>
<a class="dropdown-item" href="#">Submenu Item 4</a>
<a class="dropdown-item" href="#">Submenu Item 5</a>
<a class="dropdown-item" href="#">Submenu Item 6</a>
</div>
</div>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="icon" href="#">
<title>Home</title>
<!--BOOTSTRAP-->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="css/style.css">
<link href="https://fonts.googleapis.com/css?family=Roboto+Condensed:300,300i,400,400i|Roboto:300,300i,400,400i" rel="stylesheet">
<button class="btn btn-link navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 30 30" width="30" height="30" focusable="false"><title>Menu</title><path stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-miterlimit="10" d="M4 7h22M4 15h22M4 23h22"></path></svg>
</button>
<!-- SPLIT NAVBARS -->
<div class="btn-group navbar-collapse collapse" id="navbarsExampleDefault">
<button type="button" class="btn" id="button-1"><a href="csr-lfg.html">CSR at LF</a></button>
<button type="button" class="btn dropdown-toggle dropdown-toggle-split" id="button-1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<span class="sr-only">Toggle Dropdown</span>
</button>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Submenu Item 1</a>
<a class="dropdown-item" href="#">Submenu Item 2</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Submenu Item 3</a>
<a class="dropdown-item" href="#">Submenu Item 4</a>
<a class="dropdown-item" href="#">Submenu Item 5</a>
<a class="dropdown-item" href="#">Submenu Item 6</a>
</div>
</div>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="icon" href="#">
<title>Home</title>
<!--BOOTSTRAP-->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="css/style.css">
<link href="https://fonts.googleapis.com/css?family=Roboto+Condensed:300,300i,400,400i|Roboto:300,300i,400,400i" rel="stylesheet">
<button class="btn btn-link navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 30 30" width="30" height="30" focusable="false"><title>Menu</title><path stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-miterlimit="10" d="M4 7h22M4 15h22M4 23h22"></path></svg>
</button>
<!-- SPLIT NAVBARS -->
<div class="btn-group navbar-collapse collapse" id="navbarsExampleDefault">
<button type="button" class="btn" id="button-1"><a href="csr-lfg.html">CSR at LF</a></button>
<button type="button" class="btn dropdown-toggle dropdown-toggle-split" id="button-1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<span class="sr-only">Toggle Dropdown</span>
</button>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Submenu Item 1</a>
<a class="dropdown-item" href="#">Submenu Item 2</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Submenu Item 3</a>
<a class="dropdown-item" href="#">Submenu Item 4</a>
<a class="dropdown-item" href="#">Submenu Item 5</a>
<a class="dropdown-item" href="#">Submenu Item 6</a>
</div>
</div>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="icon" href="#">
<title>Home</title>
<!--BOOTSTRAP-->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="css/style.css">
<link href="https://fonts.googleapis.com/css?family=Roboto+Condensed:300,300i,400,400i|Roboto:300,300i,400,400i" rel="stylesheet">
<button class="btn btn-link navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 30 30" width="30" height="30" focusable="false"><title>Menu</title><path stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-miterlimit="10" d="M4 7h22M4 15h22M4 23h22"></path></svg>
</button>
<!-- SPLIT NAVBARS -->
<div class="btn-group navbar-collapse collapse" id="navbarsExampleDefault">
<button type="button" class="btn" id="button-1"><a href="csr-lfg.html">CSR at LF</a></button>
<button type="button" class="btn dropdown-toggle dropdown-toggle-split" id="button-1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<span class="sr-only">Toggle Dropdown</span>
</button>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Submenu Item 1</a>
<a class="dropdown-item" href="#">Submenu Item 2</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Submenu Item 3</a>
<a class="dropdown-item" href="#">Submenu Item 4</a>
<a class="dropdown-item" href="#">Submenu Item 5</a>
<a class="dropdown-item" href="#">Submenu Item 6</a>
</div>
</div>
菜单
切换下拉列表
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="icon" href="#">
<title>Home</title>
<!--BOOTSTRAP-->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="css/style.css">
<link href="https://fonts.googleapis.com/css?family=Roboto+Condensed:300,300i,400,400i|Roboto:300,300i,400,400i" rel="stylesheet">
<button class="btn btn-link navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 30 30" width="30" height="30" focusable="false"><title>Menu</title><path stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-miterlimit="10" d="M4 7h22M4 15h22M4 23h22"></path></svg>
</button>
<!-- SPLIT NAVBARS -->
<div class="btn-group navbar-collapse collapse" id="navbarsExampleDefault">
<button type="button" class="btn" id="button-1"><a href="csr-lfg.html">CSR at LF</a></button>
<button type="button" class="btn dropdown-toggle dropdown-toggle-split" id="button-1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<span class="sr-only">Toggle Dropdown</span>
</button>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Submenu Item 1</a>
<a class="dropdown-item" href="#">Submenu Item 2</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Submenu Item 3</a>
<a class="dropdown-item" href="#">Submenu Item 4</a>
<a class="dropdown-item" href="#">Submenu Item 5</a>
<a class="dropdown-item" href="#">Submenu Item 6</a>
</div>
</div>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="icon" href="#">
<title>Home</title>
<!--BOOTSTRAP-->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="css/style.css">
<link href="https://fonts.googleapis.com/css?family=Roboto+Condensed:300,300i,400,400i|Roboto:300,300i,400,400i" rel="stylesheet">
<button class="btn btn-link navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 30 30" width="30" height="30" focusable="false"><title>Menu</title><path stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-miterlimit="10" d="M4 7h22M4 15h22M4 23h22"></path></svg>
</button>
<!-- SPLIT NAVBARS -->
<div class="btn-group navbar-collapse collapse" id="navbarsExampleDefault">
<button type="button" class="btn" id="button-1"><a href="csr-lfg.html">CSR at LF</a></button>
<button type="button" class="btn dropdown-toggle dropdown-toggle-split" id="button-1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<span class="sr-only">Toggle Dropdown</span>
</button>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Submenu Item 1</a>
<a class="dropdown-item" href="#">Submenu Item 2</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Submenu Item 3</a>
<a class="dropdown-item" href="#">Submenu Item 4</a>
<a class="dropdown-item" href="#">Submenu Item 5</a>
<a class="dropdown-item" href="#">Submenu Item 6</a>
</div>
</div>
您错过了bootstrap.js和pooper.js，您可以在下拉列表中找到更多信息（用于按钮）
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<link rel="icon" href="#">
<title>Home</title>
<!--BOOTSTRAP-->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" integrity="sha384-WskhaSGFgHYWDcbwN70/dfYBj47jz9qbsMId/iRN3ewGhXQFZCSftd1LZCfmhktB" crossorigin="anonymous">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="css/style.css">
<link href="https://fonts.googleapis.com/css?family=Roboto+Condensed:300,300i,400,400i|Roboto:300,300i,400,400i" rel="stylesheet">
<button class="btn btn-link navbar-toggler collapsed" type="button" data-toggle="collapse" data-target="#navbarsExampleDefault" aria-controls="navbarsExampleDefault" aria-expanded="false" aria-label="Toggle navigation">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 30 30" width="30" height="30" focusable="false"><title>Menu</title><path stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-miterlimit="10" d="M4 7h22M4 15h22M4 23h22"></path></svg>
</button>
<!-- SPLIT NAVBARS -->
<div class="btn-group navbar-collapse collapse" id="navbarsExampleDefault">
<button type="button" class="btn" id="button-1"><a href="csr-lfg.html">CSR at LF</a></button>
<button type="button" class="btn dropdown-toggle dropdown-toggle-split" id="button-1" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<span class="sr-only">Toggle Dropdown</span>
</button>
<div class="dropdown-menu">
<a class="dropdown-item" href="#">Submenu Item 1</a>
<a class="dropdown-item" href="#">Submenu Item 2</a>
<div class="dropdown-divider"></div>
<a class="dropdown-item" href="#">Submenu Item 3</a>
<a class="dropdown-item" href="#">Submenu Item 4</a>
<a class="dropdown-item" href="#">Submenu Item 5</a>
<a class="dropdown-item" href="#">Submenu Item 6</a>
</div>
</div>
切换下拉列表