【发布时间】：2020-12-31 12:46:13
【问题描述】：
我正在使用 Bootstrap 4，并且我有如下多级下拉菜单：
我想把子菜单拉到左边。所以它目前显示的另一面。我使用了多个类，例如dropdown-menu-left、pull-left、dropleft，但没有改变拉子菜单的方向。
我还覆盖了下拉菜单类，但结果相同。
.dropdown-menu {
left: auto;
right: 0;
}
任何建议请在 Boostrap 4 中将子菜单拉到左侧的正确类是什么？我在这里尝试了其他线程的解决方案，但它对我不起作用。非常感谢。
这是我的代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Bootstrap 4 Navbar With Multilevel Dropdowns Example</title>
<link href="https://www.jqueryscript.net/css/jquerysctipttop.css" rel="stylesheet" type="text/css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootswatch/4.3.1/lumen/bootstrap.min.css">
<style>
.dropdown-submenu {
position: relative;
}
.dropdown-submenu a::after {
transform: rotate(-90deg);
position: absolute;
right: 6px;
top: .8em;
}
.dropdown-submenu .dropdown-menu {
top: 0;
left: 100%;
margin-left: .1rem;
margin-right: .1rem;
}
</style>
</head>
<body>
<nav class="navbar navbar-expand-lg">
<div class="collapse navbar-collapse" id="navbarNavDropdown">
<ul class="navbar-nav">
<li class="nav-item active">
<a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
</li>
<li class="nav-item active">
<a class="nav-link" href="#">Home 2</a>
</li>
<li class="nav-item active">
<a class="nav-link" href="#">Home 3</a>
</li>
<li class="nav-item active">
<a class="nav-link" href="#">Home 4</a>
</li>
<li class="nav-item active">
<a class="nav-link" href="#">Home 5</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="http://example.com" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
Dropdown link
</a>
<ul class="dropdown-menu" aria-labelledby="navbarDropdownMenuLink">
<li><a class="dropdown-item" href="#">Action</a></li>
<li><a class="dropdown-item" href="#">Another action</a></li>
<li class="dropdown-submenu">
<a class="dropdown-item dropdown-toggle" href="#">Submenu</a>
<ul class="dropdown-menu">
<li><a class="dropdown-item" href="#">Submenu action</a></li>
<li><a class="dropdown-item" href="#">Another submenu action</a></li>
<li class="dropdown-submenu">
<a class="dropdown-item dropdown-toggle" href="#">Subsubmenu</a>
<ul class="dropdown-menu">
<li><a class="dropdown-item" href="#">Subsubmenu action</a></li>
<li><a class="dropdown-item" href="#">Another subsubmenu action</a></li>
</ul>
</li>
<li class="dropdown-submenu">
<a class="dropdown-item dropdown-toggle" href="#">Second subsubmenu</a>
<ul class="dropdown-menu">
<li><a class="dropdown-item" href="#">Subsubmenu action</a></li>
<li><a class="dropdown-item" href="#">Another subsubmenu action</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
</nav>
<script src="https://code.jquery.com/jquery-3.4.1.slim.min.js" integrity="sha384-J6qa4849blE2+poT4WnyKhv5vZF5SrPo0iEjwBvKU7imGFAV0wwj1yYfoRSJoZ+n" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.0/dist/umd/popper.min.js" integrity="sha384-Q6E9RHvbIyZFJoft+2mJbHaEWldlvI9IOYy5n3zV9zzTtmI3UksdQRVvoxMfooAo" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js" integrity="sha384-wfSDF2E50Y2D1uUdj0O3uMBJnjuUD4Ih7YwaYd1iqfktj0Uod8GCExl3Og8ifwB6" crossorigin="anonymous"></script>
<script>
$('.dropdown-menu a.dropdown-toggle').on('click', function(e) {
if (!$(this).next().hasClass('show')) {
$(this).parents('.dropdown-menu').first().find('.show').removeClass('show');
}
var $subMenu = $(this).next('.dropdown-menu');
$subMenu.toggleClass('show');
$(this).parents('li.nav-item.dropdown.show').on('hidden.bs.dropdown', function(e) {
$('.dropdown-submenu .show').removeClass('show');
});
return false;
});
</script>
</body>
</html>
【问题讨论】：
-
@KurtChun 是的，它包含在 jquery 之后
-
尝试将你的 popper.js 移动到 html 而不是
-
作为这个演示，将 jquery 和 popper.js 放到 标签 tutorialrepublic.com/…
-
@KurtChun 感谢您的宝贵时间。我试过了，结果还是一样
标签： html css twitter-bootstrap bootstrap-4 drop-down-menu