目前，V4 似乎没有关于使用导航栏下拉菜单的文档。按照 V3 文档，V4 上的导航栏确实会在单击时下拉，但似乎没有样式。如何使下拉菜单正确显示，如图所示 in the V3 docs ？我假设 css 选择器已经改变；如果是这样，我将如何找到新的未记录的选择器？
这是 V4 库中的 V3 类目前的样子:
使用的 HTML:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"/>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.2/css/bootstrap.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.0/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.2/js/bootstrap.min.js"></script>
</head>
<body>
<nav class="navbar navbar-fixed-top navbar-dark bg-inverse">
<a class="navbar-brand" href="/">HelloWorld</a>
<ul class="nav navbar-nav">
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true"
aria-expanded="false">1<span class="caret"></span></a>
<ul class="dropdown-menu">
<li><a href="#">Map</a></li>
<li><a href="#">Grid</a></li>
</ul>
</li>
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true"
aria-expanded="false">2<span class="caret"></span></a>
<ul class="dropdown-menu">
<li><a href="#">Map</a></li>
<li><a href="#">Grid</a></li>
</ul>
</li>
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true"
aria-expanded="false">3<span class="caret"></span></a>
<ul class="dropdown-menu">
<li><a href="#">Map</a></li>
<li><a href="#">Grid</a></li>
</ul>
</li>
<li class="nav-item"><a class="nav-link" href="">Test</a></li>
</ul>
<ul class="nav navbar-nav pull-xs-right">
<li class="nav-item"><a class="nav-link" href="">Logout </a></li>
</ul>
</nav>
</body>
</html>
最佳答案
您正在使用
<li> and <ul>而文档建议使用 <div> and <a>标签代替
<div class="dropdown">
<button class="btn btn-success dropdown-toggle" type="button" id="dropdownMenu2" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
1
</button>
<div class="dropdown-menu" aria-labelledby="dropdownMenu2">
<button class="dropdown-item" type="button">Action</button>
<button class="dropdown-item" type="button">Another action</button>
<button class="dropdown-item" type="button">Something else here</button>
</div>
</div>
编辑:Fiddle供引用
Edit2:好的，所以你错过了类(class) btn and btn-success .同时添加 css 规则
.dropdown { display:inline-block;}
编辑 3:Fiddle Link : 下拉列表 1 <a>而不是 <button>
关于css - Twitter-Bootstrap V4 导航栏下拉菜单缺少样式，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/35077980/