我正在此导航栏上使用最新的引导程序4，我想在中小型屏幕上使用切换按钮。但是，该按钮不起作用并且没有显示菜单项。
包裹入（nav class =“ navbar navbar-expand-lg navbar-dark sticky-top”）
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navigationCollapse">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="#navigationCollapse">
<ul class="navbar-nav ml-auto">
<li class="list-item">
<a href="#" class="nav-link">Home</a>
</li>
<li class="list-item">
<a href="#" class="nav-link">About</a>
</li>
<li class="list-item">
<a href="#" class="nav-link">Services</a>
</li>
<li class="list-item">
<a href="#" class="nav-link">Team</a>
</li>
<li class="list-item">
<a href="#" class="nav-link">Contact</a>
</li>
</ul>
</div>
You need to make 2 changes - First,
<li class="list-item">to<li class="nav-item">and secondid="#navigationCollapse"toid="navigationCollapse". We use # only where we are referring to this id.Additionally i used
<nav class="navbar navbar-expand-lg navbar-light sticky-top">as nav.View JS Fiddle