菜单展开及收缩效果 bootstrap+jquery

        $(".mymenu").click(function () {
            var mymenu = $(this.parentElement);
            $(".treeview-menu").slideUp("slow", function () {
                $(".active").toggleClass("active treeview")
                //收起其他打开的菜单
                $(".glyphicon-menu-down").toggleClass("glyphicon-menu-down glyphicon-menu-left");
            });
            if ($(this.parentElement.lastElementChild).attr("style") == "display: none;" || $(this.parentElement.lastElementChild).attr("style") == undefined) {
                $(this.parentElement.lastElementChild).slideDown("slow", function () {
                    //sidedown收起完成后的操作
                    mymenu.toggleClass("active treeview");
                    //更新图标
                    $(this.parentElement.firstElementChild.lastElementChild).toggleClass("glyphicon-menu-down glyphicon-menu-left");
                });
            }
        });
        $("._menuitem").click(function () {
            $("._menuitem").removeClass("active");
            $(this).toggleClass("active");
        });

      <ul class="sidebar-menu" id="siderbar-menu">
                    <li class="header">主菜单</li>
                    <li class="treeview">
                        <a href="#" class="mymenu">
                            <i class="glyphicon glyphicon-dashboard"></i> <span>菜单A</span> <span class="glyphicon glyphicon-menu-left pull-right"></span>
                        </a>
                        <ul class="treeview-menu amenu">
                            <li class="_menuitem"><a href="#"><i class="glyphicon glyphicon-unchecked text-aqua"></i> 菜单A1</a></li>
                            <li class="_menuitem"><a href="#"><i class="glyphicon glyphicon-unchecked text-aqua"></i> 菜单A2</a></li>
                        </ul>
                    </li>

                    <li class="treeview">
                        <a href="#" class="mymenu">
                            <i class="glyphicon glyphicon-asterisk"></i>
                            <span>菜单B</span>
                            <span class="label label-primary pull-right">4</span>
                        </a>
                        <ul class="treeview-menu">
                            <li class="_menuitem"><a href="#"><i class="glyphicon glyphicon-unchecked text-aqua"></i> 菜单B1</a></li>
                            <li class="_menuitem"><a href="#"><i class="glyphicon glyphicon-unchecked text-aqua"></i> 菜单B2</a></li>
                            <li class="_menuitem"><a href="#"><i class="glyphicon glyphicon-unchecked text-aqua"></i> 菜单B3</a></li>
                            <li class="_menuitem"><a href="#"><i class="glyphicon glyphicon-unchecked text-aqua"></i> 菜单B4</a></li>
                        </ul>

                    </li>
                    <li class="treeview">
                        <a href="#">
                            <i class="glyphicon glyphicon-object-align-vertical"></i>
                            <span>菜单C 无 子菜单</span>
                            <small class="label pull-right bg-green">new</small>
                        </a>
                    </li>
                    <li class="treeview">
                        <a href="#" class="mymenu">
                            <i class="glyphicon glyphicon-blackboard"></i>
                            <span>菜单D</span>
                            <span class="glyphicon glyphicon-menu-left pull-right"></span>
                        </a>
                        <ul class="treeview-menu">
                            <li class="_menuitem"><a href="#"><i class="glyphicon glyphicon-unchecked text-green"></i> 菜单D1</a></liclass>
                            <li class="_menuitem"><a href="#"><i class="glyphicon glyphicon-unchecked text-aqua"></i> 菜单D2</a></li>
                            <li class="_menuitem"><a href="#"><i class="glyphicon glyphicon-unchecked text-aqua"></i> 菜单D3</a></li>
                            <li class="_menuitem"><a href="#"><i class="glyphicon glyphicon-unchecked text-aqua"></i> 菜单D4</a></liclass>
                        </ul>
                    </li>
                    <li class="header">图例</li>
                    <li><a href="#"><i class="glyphicon glyphicon-unchecked text-red"></i> <span>重要</span></a></li>
                    <li><a href="#"><i class="glyphicon glyphicon-unchecked text-yellow"></i> <span>警告</span></a></li>
                    <li><a href="#"><i class="glyphicon glyphicon-unchecked text-aqua"></i> <span>消息</span></a></li>
                </ul>