你好朋友我有一个下拉菜单，它会随着点击而显示和消失。
但是当我第三次点击列表时，会出现整个列表（多个丢弃显示为未关闭）。如何使列表显示在默认结构中？
这是我的代码。请帮忙。
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js">
</script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js">
</script>
<style>
.dropdown-submenu {
position: relative;
}
.dropdown-submenu .dropdown-menu {
top: 0;
left: 100%;
margin-top: -1px;
}
</style>
</head>
<body>
<div class="container">
<h2>Multi-Level Dropdowns</h2>
<p>In this example, we have created a .dropdown-submenu class for multi-level dropdowns (see style section above).</p>
<p>Note that we have added jQuery to open the multi-level dropdown on click (see script section below).</p>
<div class="dropdown">
<button class="btn btn-default dropdown-toggle" type="button" data-toggle="dropdown">Tutorials
<span class="caret"></span></button>
<ul class="dropdown-menu">
<li><a tabindex="-1" href="#">HTML</a></li>
<li><a tabindex="-1" href="#">CSS</a></li>
<li class="dropdown-submenu">
<a class="test" tabindex="-1" href="#">New dropdown <span class="caret"></span></a>
<ul class="dropdown-menu">
<li><a tabindex="-1" href="#">2nd level dropdown</a></li>
<li><a tabindex="-1" href="#">2nd level dropdown</a></li>
<li class="dropdown-submenu">
<a class="test" href="#">Another dropdown <span class="caret"></span></a>
<ul class="dropdown-menu">
<li><a href="#">3rd level dropdown</a></li>
<li><a href="#">3rd level dropdown</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
</div>
<script>
$(document).ready(function() {
$('.dropdown-submenu a.test').on("click", function(e) {
$(this).next('ul').toggle();
e.stopPropagation();
e.preventDefault();
});
});
</script>
</body>
</html>
答案 0 :(得分：0)
当主下拉列表关闭时，您需要隐藏子下拉列表。
您可以通过收听hide.bs.dropdown事件来执行此操作。
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js">
</script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js">
</script>
<style>
.dropdown-submenu {
position: relative;
}
.dropdown-submenu .dropdown-menu {
top: 0;
left: 100%;
margin-top: -1px;
}
</style>
</head>
<body>
<div class="container">
<h2>Multi-Level Dropdowns</h2>
<p>In this example, we have created a .dropdown-submenu class for multi-level dropdowns (see style section above).</p>
<p>Note that we have added jQuery to open the multi-level dropdown on click (see script section below).</p>
<div class="dropdown">
<button class="btn btn-default dropdown-toggle" type="button" data-toggle="dropdown">Tutorials
<span class="caret"></span></button>
<ul class="dropdown-menu">
<li><a tabindex="-1" href="#">HTML</a></li>
<li><a tabindex="-1" href="#">CSS</a></li>
<li class="dropdown-submenu">
<a class="test" tabindex="-1" href="#">New dropdown <span class="caret"></span></a>
<ul class="dropdown-menu">
<li><a tabindex="-1" href="#">2nd level dropdown</a></li>
<li><a tabindex="-1" href="#">2nd level dropdown</a></li>
<li class="dropdown-submenu">
<a class="test" href="#">Another dropdown <span class="caret"></span></a>
<ul class="dropdown-menu">
<li><a href="#">3rd level dropdown</a></li>
<li><a href="#">3rd level dropdown</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
</div>
<script>
$(document).ready(function() {
$('.dropdown-submenu a.test').on("click", function(e) {
$(this).next('ul').toggle();
e.stopPropagation();
e.preventDefault();
});
});
$('.dropdown').on('hide.bs.dropdown', function() {
$('.dropdown-submenu .dropdown-menu').hide();
});
</script>
</body>
</html>