Bootstrap树形菜单，就这么简单

一、CSS部分：

.tree {    min-height:20px;    padding:19px;    margin-bottom:20px;    background-color:#fbfbfb;    border:1px solid #999;    -webkit-border-radius:4px;    -moz-border-radius:4px;    border-radius:4px;    -webkit-box-shadow:inset 0 1px 1px rgba(0, 0, 0, 0.05);    -moz-box-shadow:inset 0 1px 1px rgba(0, 0, 0, 0.05);    box-shadow:inset 0 1px 1px rgba(0, 0, 0, 0.05)}.tree li {    list-style-type:none;    margin:0;    padding:10px 5px 0 5px;    position:relative}.tree li::before, .tree li::after {    content:'';    left:-20px;    position:absolute;    right:auto}.tree li::before {    border-left:1px solid #999;    bottom:50px;    height:100%;    top:0;    width:1px}.tree li::after {    border-top:1px solid #999;    height:20px;    top:25px;    width:25px}.tree li span {    -moz-border-radius:5px;    -webkit-border-radius:5px;    border:1px solid #999;    border-radius:5px;    display:inline-block;    padding:3px 8px;    text-decoration:none}.tree li.parent_li>span {    cursor:pointer}.tree>ul>li::before, .tree>ul>li::after {    border:0}.tree li:last-child::before {    height:30px}.tree li.parent_li>span:hover, .tree li.parent_li>span:hover+ul li span {    background:#eee;    border:1px solid #94a0b4;    color:#000}.icon-plus-sign{display:inline-block;width:16px;height:16px;background:url('../Images/bg/ico_small.png') left -44px no-repeat;}.icon-minus-sign{display:inline-block;width:16px;height:16px;background:url('../Images/bg/ico_small.png') left 0px no-repeat;}

完全可以自己建一个Css文件，将他们考入，引用。

.tree li::before, .tree li::after {}.tree li::before {}.tree li::after {}

主要用上面三个属性实现树的前面树形线，注意是用css3的before 和after实现

二、HTML部分：

 <div class="tree well">            <ul>                <li>                    <span><i class="icon-plus-sign"></i> Parent</span><a href="">Goes somewhere</a>                    <ul>                        <li>                            <span><i class="icon-plus-sign"></i> Child</span> <a href="">Goes somewhere</a>                            <ul>                                <li>                                    <span><i class="icon-leaf"></i> Grand Child</span> <a href="">Goes somewhere</a>                                </li>                            </ul>                        </li>                        <li>                            <span><i class="icon-plus-sign"></i> Child</span> <a href="">Goes somewhere</a>                            <ul>                                <li>                                    <span><i class="icon-leaf"></i> Grand Child</span> <a href="">Goes somewhere</a>                                </li>                                <li>                                    <span><i class="icon-plus-sign"></i> Grand Child</span> <a href="">Goes somewhere</a>                                    <ul>                                        <li>                                            <span><i class="icon-plus-sign"></i> Great Grand Child</span> <a href="">Goes somewhere</a>                                            <ul>                                                <li>                                                    <span><i class="icon-leaf"></i> Great great Grand Child</span> <a href="">Goes somewhere</a>                                                </li>                                                <li>                                                    <span><i class="icon-leaf"></i> Great great Grand Child</span> <a href="">Goes somewhere</a>                                                </li>                                            </ul>                                        </li>                                        <li>                                            <span><i class="icon-leaf"></i> Great Grand Child</span> <a href="">Goes somewhere</a>                                        </li>                                        <li>                                            <span><i class="icon-leaf"></i> Great Grand Child</span> <a href="">Goes somewhere</a>                                        </li>                                    </ul>                                </li>                                <li>                                    <span><i class="icon-leaf"></i> Grand Child</span> <a href="">Goes somewhere</a>                                </li>                            </ul>                        </li>                    </ul>                </li>                <li>                    <span><i class="icon-plus-sign"></i> Parent2</span> <a href="">Goes somewhere</a>                    <ul>                        <li>                            <span><i class="icon-leaf"></i> Child</span> <a href="">Goes somewhere</a>                        </li>                    </ul>                </li>            </ul>        </div>

三、JQ:

   <script type="text/javascript">        var d=true;        $(function () {            $('.tree li:has(ul)').addClass('parent_li').find(' > span').attr('title', 'Collapse this branch');            $('.tree li.parent_li > span').on('click', function (e) {                var d = $(this).siblings('ul').is(":visible");                $(this).siblings('ul').slideToggle('fast');//.siblings('dt').css('background-position','right -40px');                if (d) {                    console.log($(this).find(">i"));                    $(this).find(">i").addClass('icon-minus-sign').removeClass('icon-plus-sign');                                    } else {                  //  $(this).find(' > i').addClass('icon-minus-sign').removeClass('icon-plus-sign');                    $(this).find(">i").addClass('icon-plus-sign').removeClass('icon-minus-sign');                }                e.stopPropagation();            });        });    </script>

4、树形折叠图片：

为这两个样式准备

.icon-plus-sign{display:inline-block;width:16px;height:16px;background:url('../Images/bg/ico_small.png') left -44px no-repeat;}.icon-minus-sign{display:inline-block;width:16px;height:16px;background:url('../Images/bg/ico_small.png') left 0px no-repeat;}