实现目标:
1、访问 Bootstrap5-navbar
2、修改dropdown为多级
<!DOCTYPE HTML>
<html lang="en-US">
<head>
<meta charset="UTF-8">
<title></title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta3/dist/css/bootstrap.min.css">
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta3/dist/js/bootstrap.min.js"></script>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-light bg-light">
<div class="container-fluid">
<a class="navbar-brand" href="#">Navbar</a>
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav me-auto mb-2 mb-lg-0">
<li class="nav-item">
<a class="nav-link active" aria-current="page" href="#">Home</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Link</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
Dropdown
</a>
<ul class="dropdown-menu" aria-labelledby="navbarDropdown">
<li><a class="dropdown-item" href="#">Action</a></li>
<li><a class="dropdown-item" href="#">Another action</a></li>
<li><hr class="dropdown-divider"></li>
<li><a class="dropdown-item" href="#">Something else here</a></li>
<li class="nav-item dropdown drop-down02">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
Dropdown
</a>
<ul class="dropdown-menu sub-menu02" aria-labelledby="navbarDropdown">
<li><a class="dropdown-item" href="#">Action</a></li>
<li><a class="dropdown-item" href="#">Another action</a></li>
<li><hr class="dropdown-divider"></li>
<li><a class="dropdown-item" href="#">Something else here</a></li>
<li class="nav-item dropdown drop-down02">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
Dropdown
</a>
<ul class="dropdown-menu sub-menu02" aria-labelledby="navbarDropdown">
<li><a class="dropdown-item" href="#">Action</a></li>
<li><a class="dropdown-item" href="#">Another action</a></li>
<li><hr class="dropdown-divider"></li>
<li><a class="dropdown-item" href="#">Something else here</a></li>
<li class="nav-item dropdown drop-down02">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
Dropdown
</a>
<ul class="dropdown-menu sub-menu02" aria-labelledby="navbarDropdown">
<li><a class="dropdown-item" href="#">Action</a></li>
<li><a class="dropdown-item" href="#">Another action</a></li>
<li><hr class="dropdown-divider"></li>
<li><a class="dropdown-item" href="#">Something else here</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#" tabindex="-1" aria-disabled="true">Disabled</a>
</li>
</ul>
<form class="d-flex">
<input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
<button class="btn btn-outline-success" type="submit">Search</button>
</form>
</div>
</div>
</nav>
</body>
</html>
3、完成之后访问
这时如果你点击第二个dropdown,它是不会展开内容的,因为我们自定义了多级dropdown,而bootstrap5只定义了单个dropdown点击事件 ,此时就要解决问题。继续。。。
4、处理多级dropdown点击事件
这里我提供一个js脚本文件,引入脚本文件就能实现。
bootstrap5-dropdown.js
(function($bs) {
const CLASS_NAME = 'has-child-dropdown-show';
$bs.Dropdown.prototype.toggle = function(_orginal) {
return function() {
document.querySelectorAll('.' + CLASS_NAME).forEach(function(e) {
e.classList.remove(CLASS_NAME);
});
let dd = this._element.closest('.dropdown').parentNode.closest('.dropdown');
for (; dd && dd !== document; dd = dd.parentNode.closest('.dropdown')) {
dd.classList.add(CLASS_NAME);
}
return _orginal.call(this);
}
}($bs.Dropdown.prototype.toggle);
document.querySelectorAll('.dropdown').forEach(function(dd) {
dd.addEventListener('hide.bs.dropdown', function(e) {
if (this.classList.contains(CLASS_NAME)) {
this.classList.remove(CLASS_NAME);
e.preventDefault();
}
if(e.clickEvent && e.clickEvent.composedPath().some(el=>el.classList && el.classList.contains('dropdown-toggle'))){
e.preventDefault();
}
e.stopPropagation(); // do not need pop in multi level mode
});
});
// for hover
function getDropdown(element) {
return $bs.Dropdown.getInstance(element) || new $bs.Dropdown(element);
}
document.querySelectorAll('.dropdown-hover, .dropdown-hover-all .dropdown').forEach(function(dd) {
dd.addEventListener('mouseenter', function(e) {
let toggle = e.target.querySelector(':scope>[data-bs-toggle="dropdown"]');
if (!toggle.classList.contains('show')) {
getDropdown(toggle).toggle();
}
});
dd.addEventListener('mouseleave', function(e) {
let toggle = e.target.querySelector(':scope>[data-bs-toggle="dropdown"]');
if (toggle.classList.contains('show')) {
getDropdown(toggle).toggle();
}
});
});
})(bootstrap);
5、访问看看
看看显示有点丑,美化一下
6、美化dropdown
自定义样式
分别找到dropdown修改关键内容:
<li class="nav-item dropdown drop-down02">
<ul class="dropdown-menu sub-menu02" aria-labelledby="navbarDropdown">
自定义样式文件:style.css
.drop-down02{
position:relative;
}
.drop-down02 .sub-menu02
{
position: absolute !important;
left: 100%;
top: 0;
}
.drop-down02 .dropdown-toggle{
padding:.25rem 1.1rem !important;
}
@media screen and (max-width :767px)
{
.drop-down02 .sub-menu02
{
position:static !important;
}
}
7、完整代码
index.html
<!DOCTYPE HTML>
<html lang="en-US">
<head>
<meta charset="UTF-8">
<title></title>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta3/dist/css/bootstrap.min.css">
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0-beta3/dist/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="/static/css/style.css" />
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-light bg-light">
<div class="container-fluid">
<a class="navbar-brand" href="#">Navbar</a>
<button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse" id="navbarSupportedContent">
<ul class="navbar-nav me-auto mb-2 mb-lg-0">
<li class="nav-item">
<a class="nav-link active" aria-current="page" href="#">Home</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#">Link</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
Dropdown
</a>
<ul class="dropdown-menu" aria-labelledby="navbarDropdown">
<li><a class="dropdown-item" href="#">Action</a></li>
<li><a class="dropdown-item" href="#">Another action</a></li>
<li><hr class="dropdown-divider"></li>
<li><a class="dropdown-item" href="#">Something else here</a></li>
<li class="nav-item dropdown drop-down02">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
Dropdown
</a>
<ul class="dropdown-menu sub-menu02" aria-labelledby="navbarDropdown">
<li><a class="dropdown-item" href="#">Action</a></li>
<li><a class="dropdown-item" href="#">Another action</a></li>
<li><hr class="dropdown-divider"></li>
<li><a class="dropdown-item" href="#">Something else here</a></li>
<li class="nav-item dropdown drop-down02">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
Dropdown
</a>
<ul class="dropdown-menu sub-menu02" aria-labelledby="navbarDropdown">
<li><a class="dropdown-item" href="#">Action</a></li>
<li><a class="dropdown-item" href="#">Another action</a></li>
<li><hr class="dropdown-divider"></li>
<li><a class="dropdown-item" href="#">Something else here</a></li>
<li class="nav-item dropdown drop-down02">
<a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-bs-toggle="dropdown" aria-expanded="false">
Dropdown
</a>
<ul class="dropdown-menu sub-menu02" aria-labelledby="navbarDropdown">
<li><a class="dropdown-item" href="#">Action</a></li>
<li><a class="dropdown-item" href="#">Another action</a></li>
<li><hr class="dropdown-divider"></li>
<li><a class="dropdown-item" href="#">Something else here</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
<li class="nav-item">
<a class="nav-link disabled" href="#" tabindex="-1" aria-disabled="true">Disabled</a>
</li>
</ul>
<form class="d-flex">
<input class="form-control me-2" type="search" placeholder="Search" aria-label="Search">
<button class="btn btn-outline-success" type="submit">Search</button>
</form>
</div>
</div>
</nav>
<!-- 这里 引入 bootstrap5-dropdown.js -->
<script src="/static/js/bootstrap5-dropdown.js"></script>
</body>
</html>
style.css
.drop-down02{
position:relative;
}
.drop-down02 .sub-menu02
{
position: absolute !important;
left: 100%;
top: 0;
}
.drop-down02 .dropdown-toggle{
padding:.25rem 1.1rem !important;
}
@media screen and (max-width :767px)
{
.drop-down02 .sub-menu02
{
position:static !important;
}
}
bootstrap5-dropdown.js
(function($bs) {
const CLASS_NAME = 'has-child-dropdown-show';
$bs.Dropdown.prototype.toggle = function(_orginal) {
return function() {
document.querySelectorAll('.' + CLASS_NAME).forEach(function(e) {
e.classList.remove(CLASS_NAME);
});
let dd = this._element.closest('.dropdown').parentNode.closest('.dropdown');
for (; dd && dd !== document; dd = dd.parentNode.closest('.dropdown')) {
dd.classList.add(CLASS_NAME);
}
return _orginal.call(this);
}
}($bs.Dropdown.prototype.toggle);
document.querySelectorAll('.dropdown').forEach(function(dd) {
dd.addEventListener('hide.bs.dropdown', function(e) {
if (this.classList.contains(CLASS_NAME)) {
this.classList.remove(CLASS_NAME);
e.preventDefault();
}
if(e.clickEvent && e.clickEvent.composedPath().some(el=>el.classList && el.classList.contains('dropdown-toggle'))){
e.preventDefault();
}
e.stopPropagation(); // do not need pop in multi level mode
});
});
// for hover
function getDropdown(element) {
return $bs.Dropdown.getInstance(element) || new $bs.Dropdown(element);
}
document.querySelectorAll('.dropdown-hover, .dropdown-hover-all .dropdown').forEach(function(dd) {
dd.addEventListener('mouseenter', function(e) {
let toggle = e.target.querySelector(':scope>[data-bs-toggle="dropdown"]');
if (!toggle.classList.contains('show')) {
getDropdown(toggle).toggle();
}
});
dd.addEventListener('mouseleave', function(e) {
let toggle = e.target.querySelector(':scope>[data-bs-toggle="dropdown"]');
if (toggle.classList.contains('show')) {
getDropdown(toggle).toggle();
}
});
});
})(bootstrap);
8、最终访问页面