Bootstrap 多级下拉菜单

小开

最佳答案

Updated Answer

^{* Updated answer which support the v2.1.1** bootstrap version stylesheet.}

^{**But be careful because this solution has been removed from v3}

Just wanted to point out that this solution is not needed anymore as the latest bootstrap now supports multi-level dropdowns by default. You can still use it if you're on older versions but for those who updated to the latest (v2.1.1 at the time of writing) it is not needed anymore. Here is a fiddle with the updated default multi-level dropdown straight from the documentation:

http://jsfiddle.net/2Smgv/2858/

Original Answer

There have been some issues raised on submenu support over at github and they are usually closed by the bootstrap developers, such as this one, so i think it is left to the developers using the bootstrap to work something out. Here is a demo i put together showing you how you can hack together a working sub-menu.

Relevant code

CSS

.dropdown-menu .sub-menu {
left: 100%;
position: absolute;
top: 0;
visibility: hidden;
margin-top: -1px;
}


.dropdown-menu li:hover .sub-menu {
visibility: visible;
display: block;
}


.navbar .sub-menu:before {
border-bottom: 7px solid transparent;
border-left: none;
border-right: 7px solid rgba(0, 0, 0, 0.2);
border-top: 7px solid transparent;
left: -7px;
top: 10px;
}
.navbar .sub-menu:after {
border-top: 6px solid transparent;
border-left: none;
border-right: 6px solid #fff;
border-bottom: 6px solid transparent;
left: 10px;
top: 11px;
left: -6px;
}

Created my own .sub-menu class to apply to the 2-level drop down menus, this way we can position them next to our menu items. Also modified the arrow to display it on the left of the submenu group.

Demo

小开

I just added class="span2" to the <li> for the dropdown items and that worked.

小开

I was able to fix the sub-menu's always pinning to the top of the parent menu from Andres's answer with the following addition:

.dropdown-menu li {
position: relative;
}

I also add an icon "icon-chevron-right" on items which contain menu sub-menus, and change the icon from black to white on hover (to compliment the text changing to white and look better with the selected blue background).

Here is the full less/css change (replace the above with this):

.dropdown-menu li {
position: relative;


[class^="icon-"] {
float: right;
}


&:hover {
// Switch to white icons on hover
[class^="icon-"] {
background-image: url("../img/glyphicons-halflings-white.png");
}
}
}

小开

[Twitter Bootstrap v3]

To create a n-level dropdown menu (touch device friendly) in Twitter Bootstrap v3,

jsfiddle-demo of n-level dropdown menu v3.0.0 | v3.1.1 | v3.3.0

CSS:

.dropdown-menu>li /* To prevent selection of text */
{   position:relative;
-webkit-user-select: none; /* Chrome/Safari */
-moz-user-select: none; /* Firefox */
-ms-user-select: none; /* IE10+ */
/* Rules below not implemented in browsers yet */
-o-user-select: none;
user-select: none;
cursor:pointer;
}
.dropdown-menu .sub-menu
{
left: 100%;
position: absolute;
top: 0;
display:none;
margin-top: -1px;
border-top-left-radius:0;
border-bottom-left-radius:0;
border-left-color:#fff;
box-shadow:none;
}
.right-caret:after,.left-caret:after
{  content:"";
border-bottom: 5px solid transparent;
border-top: 5px solid transparent;
display: inline-block;
height: 0;
vertical-align: middle;
width: 0;
margin-left:5px;
}
.right-caret:after
{   border-left: 5px solid #ffaf46;
}
.left-caret:after
{   border-right: 5px solid #ffaf46;
}

JQuery:

$(function(){
$(".dropdown-menu > li > a.trigger").on("click",function(e){
var current=$(this).next();
var grandparent=$(this).parent().parent();
if($(this).hasClass('left-caret')||$(this).hasClass('right-caret'))
$(this).toggleClass('right-caret left-caret');
grandparent.find('.left-caret').not(this).toggleClass('right-caret left-caret');
grandparent.find(".sub-menu:visible").not(current).hide();
current.toggle();
e.stopPropagation();
});
$(".dropdown-menu > li > a:not(.trigger)").on("click",function(){
var root=$(this).closest('.dropdown');
root.find('.left-caret').toggleClass('right-caret left-caret');
root.find('.sub-menu:visible').hide();
});
});

HTML:

<div class="dropdown" style="position:relative">
<a href="#" class="btn btn-primary dropdown-toggle" data-toggle="dropdown">Click Here <span class="caret"></span></a>
<ul class="dropdown-menu">
<li>
<a class="trigger right-caret">Level 1</a>
<ul class="dropdown-menu sub-menu">
<li><a href="#">Level 2</a></li>
<li>
<a class="trigger right-caret">Level 2</a>
<ul class="dropdown-menu sub-menu">
<li><a href="#">Level 3</a></li>
<li><a href="#">Level 3</a></li>
<li>
<a class="trigger right-caret">Level 3</a>
<ul class="dropdown-menu sub-menu">
<li><a href="#">Level 4</a></li>
<li><a href="#">Level 4</a></li>
<li><a href="#">Level 4</a></li>
</ul>
</li>
</ul>
</li>
<li><a href="#">Level 2</a></li>
</ul>
</li>
<li><a href="#">Level 1</a></li>
<li><a href="#">Level 1</a></li>
</ul>
</div>

小开

This example is from http://bootsnipp.com/snippets/featured/multi-level-dropdown-menu-bs3

Works for me in Bootstrap v3.1.1.

HTML

<div class="container">
<div class="row">
<h2>Multi level dropdown menu in Bootstrap 3</h2>
<hr>
<div class="dropdown">
<a id="dLabel" role="button" data-toggle="dropdown" class="btn btn-primary" data-target="#" href="/page.html">
Dropdown <span class="caret"></span>
</a>
<ul class="dropdown-menu multi-level" role="menu" aria-labelledby="dropdownMenu">
<li><a href="#">Some action</a></li>
<li><a href="#">Some other action</a></li>
<li class="divider"></li>
<li class="dropdown-submenu">
<a tabindex="-1" href="#">Hover me for more options</a>
<ul class="dropdown-menu">
<li><a tabindex="-1" href="#">Second level</a></li>
<li class="dropdown-submenu">
<a href="#">Even More..</a>
<ul class="dropdown-menu">
<li><a href="#">3rd level</a></li>
<li><a href="#">3rd level</a></li>
</ul>
</li>
<li><a href="#">Second level</a></li>
<li><a href="#">Second level</a></li>
</ul>
</li>
</ul>
</div>
</div>

CSS

.dropdown-submenu {
position: relative;
}


.dropdown-submenu>.dropdown-menu {
top: 0;
left: 100%;
margin-top: -6px;
margin-left: -1px;
-webkit-border-radius: 0 6px 6px 6px;
-moz-border-radius: 0 6px 6px;
border-radius: 0 6px 6px 6px;
}


.dropdown-submenu:hover>.dropdown-menu {
display: block;
}


.dropdown-submenu>a:after {
display: block;
content: " ";
float: right;
width: 0;
height: 0;
border-color: transparent;
border-style: solid;
border-width: 5px 0 5px 5px;
border-left-color: #ccc;
margin-top: 5px;
margin-right: -10px;
}


.dropdown-submenu:hover>a:after {
border-left-color: #fff;
}


.dropdown-submenu.pull-left {
float: none;
}


.dropdown-submenu.pull-left>.dropdown-menu {
left: -100%;
margin-left: 10px;
-webkit-border-radius: 6px 0 6px 6px;
-moz-border-radius: 6px 0 6px 6px;
border-radius: 6px 0 6px 6px;
}

小开

Since Bootstrap 3 removed the submenu part and we need to adapt ourselves the style, I think it's better to go with SmartMenu Bootstrap: https://vadikom.github.io/smartmenus/src/demo/bootstrap-navbar.html#

That would save us time on mobile responsive and style.

This plugin also very promising.