我正在一个网站上工作,我想在
Bootstrap 4.1上创建一个下拉子菜单
<div class="navbar-collapse text-center" id="navbarResponsive">
<ul class="navbar-nav ml-auto">
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
main menu
</a>
<div class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
<a class="dropdown-item" href="#">A</a>
<a class="dropdown-item" href="#">B</a>
<a class="dropdown-item" href="#">C</a>
<a class="dropdown-item" href="#">D</a>
</div>
</li>
<button type="submit" onclick="location.href='/M';" class="btn btn-default">R</button>
</ul>
</div>
问题陈述：
解决方法
这个codepen链接有你的答案：
link
基本上创建这样的结构
<li>
<a href="#" class="dropdown-toggle" data-toggle="dropdown">D <b class="caret"></b></a>
<ul class="dropdown-menu multi-level">
<li><a href="#">E</a></li>
<li><a href="#">F</a></li>
<li><a href="#">G</a></li>
<li class="divider"></li>
<li class="dropdown-submenu">
<a href="#" class="dropdown-toggle" data-toggle="dropdown">H</a>
<ul class="dropdown-menu">
<li><a href="#">I</a></li>
<li><a href="#">J</a></li>
<li><a href="#">K</a></li>
</ul>
</li>
</ul>
</li>
