因此，我正在尝试使用带有附加CSS和Jquery的Bootstrap Navbar在我的项目中创建多级导航栏。
以下是代码：
CodePen
$(function() {
// ------------------------------------------------------- //
// Multi Level dropdowns
// ------------------------------------------------------ //
$("ul.dropdown-menu [data-toggle='dropdown']").on("mouseover", function(event) {
event.preventDefault();
event.stopPropagation();
$(this).siblings().toggleClass("show");
});
$("ul.dropdown-menu [data-toggle='dropdown']").on("mouseleave", function(event) {
$(this).siblings().removeClass("show");
});
});.dropdown-submenu {
position: relative;
}
.dropdown-submenu>a:after {
content: "\f0da";
float: right;
border: none;
font-family: 'FontAwesome';
}
.dropdown-submenu>.dropdown-menu {
top: 0;
left: 100%;
margin-top: 0px;
margin-left: 0px;
}
.dropdown-item {
padding: .25rem 0.5rem!important;
}<html lang="en">
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.3.1/css/bootstrap.min.css">
<link href="https://fonts.googleapis.com/css?family=Open+Sans:400,700&display=swap" rel="stylesheet">
<link href="https://fonts.googleapis.com/css?family=Oswald:400,700&display=swap" rel="stylesheet">
<link href="https://fonts.googleapis.com/css?family=Material+Icons|Material+Icons+Outlined" rel="stylesheet" />
<link href="https://fonts.googleapis.com/css?family=Roboto:400,500&display=swap" rel="stylesheet">
<script src="https://kit.fontawesome.com/5336ef90a8.js" crossorigin="anonymous"></script>
<title>Test</title>
</head>
<body>
<!-- Navbar -->
<nav class="navbar navbar-expand-md navbar-light bg-light">
<a class="navbar-brand" href="./"> <img class="favicon" src="{{asset('img/Favicon.ico')}}" alt=""> </a>
<button class="navbar-toggler d-lg-none" type="button" data-toggle="collapse" data-target="#headerNav"
aria-controls="headerNav" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="headerNav">
<ul class="navbar-nav mr-auto">
<li class="nav-item">
<a class="nav-link" href="/">Home <span class="sr-only">(current)</span></a>
</li>
<!-- Level one dropdown -->
<li class="nav-item dropdown">
<a id="dropdownMenu1" href="#" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false"
class="nav-link dropdown-toggle">CATEGORIES</a>
<ul aria-labelledby="dropdownMenu1" class="dropdown-menu border-0 shadow">
<li class="dropdown-submenu">
<a id="dropdownMenu2" href="#" role="button" data-toggle="dropdown" aria-haspopup="true"
aria-expanded="false" class="dropdown-item dropdown-toggle">CEILING FANS</a>
<ul aria-labelledby="dropdownMenu2" class="dropdown-menu border-0 shadow">
<li>
<a tabindex="-1" href="#" class="dropdown-item">CF1</a>
</li>
<li><a href="#" class="dropdown-item">CF2</a></li>
<li><a href="#" class="dropdown-item">CF3</a></li>
</ul>
</li>
<li class="dropdown-submenu">
<a id="dropdownMenu2" href="#" role="button" data-toggle="dropdown" aria-haspopup="true"
aria-expanded="false" class="dropdown-item dropdown-toggle">TABLE FANS</a>
<ul aria-labelledby="dropdownMenu2" class="dropdown-menu border-0 shadow">
<li>
<a tabindex="-1" href="#" class="dropdown-item">TF1</a>
</li>
<li><a href="#" class="dropdown-item">TF2</a></li>
<li><a href="#" class="dropdown-item">TF3</a></li>
</ul>
</li>
<li class="dropdown-submenu">
<a id="dropdownMenu2" href="#" role="button" data-toggle="dropdown" aria-haspopup="true"
aria-expanded="false" class="dropdown-item dropdown-toggle">EXHAUST FANS</a>
<ul aria-labelledby="dropdownMenu2" class="dropdown-menu border-0 shadow">
<li>
<a tabindex="-1" href="#" class="dropdown-item">EF1</a>
</li>
<li><a href="#" class="dropdown-item">EF2</a></li>
<li><a href="#" class="dropdown-item">EF3</a></li>
</ul>
</li>
</ul>
</li>
<!-- End Level one -->
</ul>
</div>
</nav>
<!-- End Navbar -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.4.1/jquery.slim.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.15.0/umd/popper.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.3.1/js/bootstrap.min.js"></script>
<script src="https://kit.fontawesome.com/67aa126bbd.js" crossorigin="anonymous"></script>
</body>
</html>问题是我无法将鼠标悬停在CF1，CF2，CF3等...上。当我将鼠标移出其父元素（即“吊扇”）时，子菜单消失。
最佳答案
只需添加此CSS
.dropdown-submenu:hover .dropdown-menu {
display: block;
}