我想有我的引导菜单自动下拉悬停，而不是必须点击菜单标题。我还想去掉菜单标题旁边的小箭头。
当前回答
这适用于Bootstrap V4
JS:
<script>
$(function() {
$('.dropdown-hover').hover(
function() { $(this).addClass('show'); $(this).find('[data-toggle="dropdown"]').attr('aria-expanded', true); $(this).find('.dropdown-menu').addClass('show'); },
function() { $(this).removeClass('show'); $(this).find('[data-toggle="dropdown"]').attr('aria-expanded',false); $(this).find('.dropdown-menu').removeClass('show'); }
);
});
</script>
Vanilla Bootstrap 4下拉式HTML，除了添加了下拉式悬停类:
<div class="dropdown dropdown-hover">
<button class="btn btn-text dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
ABOUT
</button>
<div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<a class="dropdown-item" href="#">Something else here</a>
</div>
如果你不想通过使用.dropdown-hover类来选择性地启用悬停功能，那么只需将jquery的选择器从.dropdown-hover更改为.dropdown。
其他回答
引导版本4和5解决方案。(兼容)
这些都是使用mouseover和mouseleave事件和一些屏幕宽度检查的完整解决方案。这比纯CSS解决方案更好。
Bootstrap v5 -纯JS(用于webpack)
export class BootstrapOpenMenuHover {
/**
* Constructor.
*/
constructor() {
this.windowWidth = window.innerWidth;
this.mobileBreakPoint = 991; // Put your menu break point here, when it switches to a hamburger icon.
this.dropdownNavItems = document.querySelectorAll(".dropdown-toggle.nav-link");
this.dropdownMenuItems = document.querySelectorAll(".dropdown-menu");
this.setEventListeners();
}
/**
* Set all of our event listeners.
*/
setEventListeners() {
const _self = this;
// To be safe set the width once the dom is loaded.
window.addEventListener('load', function () {
_self.windowWidth = window.innerWidth;
});
// Keep track of the width in the event of a resize.
window.addEventListener('resize', function () {
_self.windowWidth = window.innerWidth;
});
// Bind our hover events.
if (_self.dropdownNavItems !== null) {
for (let i = 0; i < _self.dropdownNavItems.length; i++) {
// On mouse enter.
_self.dropdownNavItems[i].addEventListener('mouseenter', function () {
if (_self.windowWidth >= _self.mobileBreakPoint) {
this.classList.add('show');
this.ariaExpanded = true;
this.dataset.bsToggle = null;
// Update the .dropdown-menu
this.nextElementSibling.classList.add('show');
this.nextElementSibling.dataset.bsPopper = 'none';
}
});
// On mouse leave.
_self.dropdownNavItems[i].addEventListener('mouseleave', function () {
if (_self.windowWidth >= _self.mobileBreakPoint) {
this.classList.remove('show');
this.ariaExpanded = false;
this.dataset.bsToggle = 'dropdown';
// Update the .dropdown-menu
this.nextElementSibling.classList.remove('show');
this.nextElementSibling.dataset.bsPopper = null;
}
});
}
}
// Bind events to .dropdown-menu items.
if (_self.dropdownMenuItems !== null) {
for (let i = 0; i < _self.dropdownMenuItems.length; i++) {
// On mouse enter.
_self.dropdownMenuItems[i].addEventListener('mouseenter', function () {
if (_self.windowWidth >= _self.mobileBreakPoint) {
this.classList.add('show');
this.dataset.bsPopper = 'none';
// Update the .dropdown-toggle
this.previousElementSibling.classList.add('show');
this.previousElementSibling.ariaExpanded = true;
this.previousElementSibling.dataset.bsToggle = null;
}
});
// On mouse leave.
_self.dropdownMenuItems[i].addEventListener('mouseleave', function () {
if (_self.windowWidth >= _self.mobileBreakPoint) {
this.classList.remove('show');
this.dataset.bsPopper = null;
// Update the .dropdown-toggle
this.previousElementSibling.classList.remove('show');
this.previousElementSibling.ariaExpanded = false;
this.previousElementSibling.dataset.bsToggle = 'dropdown';
}
});
}
}
}
}
const bootstrapOpenMenuHover = new BootstrapOpenMenuHover();
Bootstrap v4方案
这将允许您遵循顶级导航链接。
这是基于桌面和移动平台设计的。随意更改BREAK_POINT变量以满足您的需要:D。
jQuery
var WINDOW_WIDTH;
var BREAK_POINT = 991;
(function ($) {
/** Set window width onload */
WINDOW_WIDTH = $(window).width(); // Returns width of browser viewport
/** Set window width if the browser is resized */
$(window).resize(function () {
WINDOW_WIDTH = $(window).width(); // Returns width of browser viewport
});
/** Dropdown menu on mouseenter */
$(".nav-item.dropdown").on('mouseenter', function () {
console.log("mouseenter");
if (WINDOW_WIDTH >= BREAK_POINT) {
// Open up the dropdown
$(this).addClass('show'); // add the class show to the li parent
$(this).children('.nav-link').removeAttr('data-toggle'); // remove the data-toggle attribute so we can click and follow link
$(this).children('.dropdown-menu').addClass('show'); // add the class show to the dropdown div sibling
}
});
/** Dropdown menu on mouseleave */
$(".nav-item.dropdown").on('mouseleave', function () {
console.log("mouseleave");
if (WINDOW_WIDTH >= BREAK_POINT) {
// Close the dropdown
$(this).removeClass('show'); // add the class show to the li parent
$(this).children('.nav-link').attr('data-toggle', 'dropdown'); // remove the data-toggle attribute so we can click and follow link
$(this).children('.dropdown-menu').removeClass('show'); // add the class show to the dropdown div sibling
}
});
});
CSS
@media(min-width: 768px) {
.dropdown-menu {
margin-top: 0; // fixes closing on slow mouse transition
}
}
<ul class="nav navbar-nav">
<li class="active"><a href="#">Link</a></li>
<li><a href="#">Link</a></li>
<li class="dropdown">
<a href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown <b class="caret"></b></a>
<ul class="dropdown-menu">
<li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
<li class="divider"></li>
<li><a href="#">Separated link</a></li>
<li class="divider"></li>
<li><a href="#">One more separated link</a></li>
</ul>
</li>
</ul>
<script>
$('ul.nav li.dropdown').hover(function() {
$(this).find('.dropdown-menu').stop(true,
true).delay(200).fadeIn(500);
}, function() {
$(this).find('.dropdown-menu').stop(true,
true).delay(200).fadeOut(500);
});
</script>
这适用于Bootstrap V4
JS:
<script>
$(function() {
$('.dropdown-hover').hover(
function() { $(this).addClass('show'); $(this).find('[data-toggle="dropdown"]').attr('aria-expanded', true); $(this).find('.dropdown-menu').addClass('show'); },
function() { $(this).removeClass('show'); $(this).find('[data-toggle="dropdown"]').attr('aria-expanded',false); $(this).find('.dropdown-menu').removeClass('show'); }
);
});
</script>
Vanilla Bootstrap 4下拉式HTML，除了添加了下拉式悬停类:
<div class="dropdown dropdown-hover">
<button class="btn btn-text dropdown-toggle" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
ABOUT
</button>
<div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
<a class="dropdown-item" href="#">Action</a>
<a class="dropdown-item" href="#">Another action</a>
<a class="dropdown-item" href="#">Something else here</a>
</div>
如果你不想通过使用.dropdown-hover类来选择性地启用悬停功能，那么只需将jquery的选择器从.dropdown-hover更改为.dropdown。
这样就把上面的隐藏起来了
.navbar .dropdown-menu:before {
display:none;
}
.navbar .dropdown-menu:after {
display:none;
}
如果你有这样一个下拉类的元素(例如):
<ul class="list-unstyled list-inline">
<li class="dropdown">
<a data-toggle="dropdown" href="#"><i class="fa fa-bars"></i> Dropdown 1</a>
<ul class="dropdown-menu">
<li><a href="">Item 1</a></li>
<li><a href="">Item 2</a></li>
<li><a href="">Item 3</a></li>
<li><a href="">Item 4</a></li>
<li><a href="">Item 5</a></li>
</ul>
</li>
<li class="dropdown">
<a data-toggle="dropdown" href="#"><i class="fa fa-user"></i> Dropdown 2</a>
<ul class="dropdown-menu">
<li><a href="">Item A</a></li>
<li><a href="">Item B</a></li>
<li><a href="">Item C</a></li>
<li><a href="">Item D</a></li>
<li><a href="">Item E</a></li>
</ul>
</li>
</ul>
然后你可以让下拉菜单自动下拉悬停，而不是必须点击它的标题，通过使用这段jQuery代码:
<script>
$('.dropdown').hover(
function() {
$(this).find('.dropdown-menu').stop(true, true).delay(200).fadeIn();
},
function() {
$(this).find('.dropdown-menu').stop(true, true).delay(200).fadeOut();
}
);
$('.dropdown-menu').hover(
function() {
$(this).stop(true, true);
},
function() {
$(this).stop(true, true).delay(200).fadeOut();
}
);
</script>
这是一个演示
这个答案依赖于@Michael的答案，我做了一些改变，并添加了一些补充，以使下拉菜单正常工作
