我想做的是使导航栏在较小的屏幕上折叠并在单击按钮时展开。 但是当我单击按钮时没有任何反应，我不知道为什么。
<nav class="navbar navbar-expand-lg navbar-light" style="background-color: #FFFFFF;">
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarToggleExternalContent" aria-controls="navbarToggleExternalContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse justify-content-center" id="navbarNavDropdown">
<a class="navbar-brand" href="index.html">
<img src="images\logo1.png" width="200" height="80" class="d-inline-block align-top" alt="">
</a>
<ul class="navbar-nav">
<li class="nav-item active">
<a class="nav-link" href="index.html">Home <span class="sr-only">(current)</span></a>
</li>
<li class="navbar-nav dropdown">
<a class="nav-link dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Behandelingen
</a>
<div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
<a class="dropdown-item" href="sportmassage.html">Sportmassage</a>
<a class="dropdown-item" href="massagetherapie.html">Massagetherapie</a>
<a class="dropdown-item" href="ontspanningsmassage.html">Ontspanningsmassage</a>
</div>
</li>
<li class="nav-item">
<a class="nav-link" href="tarieven.html">Tarieven</a>
</li>
<li class="nav-item">
<a class="nav-link" href="contact.html">Contact</a>
</li>
</ul>
</div>
</nav>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>最佳答案
切换按钮上的 data-target="#navbarToggleExternalContent" 错误。它应该与 .navbar-collapse 的 id 匹配。
通过 data- 属性了解有关 Bootstrap 4 崩溃的更多信息 here
关于jquery - 单击时折叠的 Bootstrap 导航栏不会打开，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/60325062/