cookie实现刷新不变化树形菜单

通过设置cookie来保存树形菜单的状态，在页面加载时重新读取cookie来设置菜单。

菜单的HTML结构：

 <div class="treemenu">
          <ul>
              <li>
                  <a href="#" id="treemenu_a_1">一级菜单一</a>
                  <div class="submenu" id="submenu_1">
                      <ul>
                          <li><a href="subpage/a.html" id="submenu_a_1_1">二级菜单一</a></li>
                          <li><a href="subpage/b.html" id="submenu_a_1_2">二级菜单二</a></li>
                          <li><a href="#" id="submenu_a_1_3">二级菜单三</a></li>
                          <li><a href="#" id="submenu_a_1_4">二级菜单四</a></li>
                          <li><a href="#" id="submenu_a_1_5">二级菜单五</a></li>
                      </ul>
                  </div>
              </li>
              <li>
                  <a href="#" id="treemenu_a_2">一级菜单二</a>
                  <div class="submenu" id="submenu_2">
                      <ul>
                          <li>
                              <a href="#" id="submenu_a_2_1">二级菜单一</a>
                             <div class="submenu" id="submenu_2_1">
                                 <ul>
                                     <li><a href="#" id="submenu_a_2_1_1">三级菜单一</a></li>
                                     <li><a href="#" id="submenu_a_2_1_2">三级菜单二</a></li>
                                     <li>
                                         <a href="#" id="submenu_a_2_1_3">三级菜单三</a>
                                         <div class="submenu" id="submenu_2_1_3">
                                             <ul>
                                                 <li><a href="#" id="submenu_a_2_1_3_1">四级菜单一</a></li>
                                                 <li><a href="#" id="submenu_a_2_1_3_2">四级菜单二</a></li>
                                                 <li><a href="#" id="submenu_a_2_1_3_3">四级菜单三</a></li>
                                             </ul>
                                         </div>
                                     </li>
                                 </ul>
                             </div>
                          </li>
                          <li><a href="#" id="submenu_a_2_2">二级菜单二</a></li>
                          <li><a href="#" id="submenu_a_2_3">二级菜单三</a></li>
                          <li><a href="#" id="submenu_a_2_4">二级菜单四</a></li>
                          <li><a href="#" id="submenu_a_2_5">二级菜单五</a></li>
                      </ul>
                  </div>
              </li>
              <li>
                  <a href="#" id="treemenu_a_3">一级菜单三</a>
                  <div class="submenu" id="submenu_3">
                      <ul>
                          <li><a href="#" id="submenu_a_3_1">二级菜单一</a></li>
                          <li><a href="#" id="submenu_a_3_2">二级菜单二</a></li>
                          <li><a href="#" id="submenu_a_3_3">二级菜单三</a></li>
                          <li><a href="#" id="submenu_a_3_4">二级菜单四</a></li>
                          <li><a href="#" id="submenu_a_3_5">二级菜单五</a></li>
                      </ul>
                  </div>
              </li>
          </ul>
      </div>

读取cookie工具类：

 //cookie工具类
 var cookieTool = {
     //读取cookie
     getCookie: function(c_name) {
         if (document.cookie.length > 0) {
             c_start = document.cookie.indexOf(c_name + "=");
             if (c_start != -1) {
                 c_start = c_start + c_name.length + 1;
                 c_end = document.cookie.indexOf(";", c_start);
                 if (c_end == -1) {
                     c_end = document.cookie.length;
                 }
                 return unescape(document.cookie.substring(c_start, c_end));
             }
         }
         return "";
     },
     //设置cookie
     setCookie: function(c_name, value, expiredays) {
         var exdate = new Date();
         exdate.setDate(exdate.getDate() + expiredays); //设置日期
         document.cookie = c_name + "=" + escape(value) + ((expiredays == null) ? "" : ";expires=" + exdate.toGMTString());
     },
     //删除cookie
     delCookie: function(c_name) {
         var exdate = new Date();
         exdate.setDate(exdate.getDate() - 1); //昨天日期
         document.cookie = c_name + "=;expires=" + exdate.toGMTString();
     }
 };

菜单事件绑定：

 //菜单事件绑定
     $('.treemenu a').bind('click', function() {
         var $this = $(this);
         var id = $this.attr('id');
         var $submenu = $this.next('.submenu');
         if ($submenu.length > 0) { //是否有子菜单
             var flag = $(this).next('.submenu:hidden').length > 0 ? true : false;
             if (flag) {
                 $submenu.show();
             } else {
                 $submenu.hide();
             }
             var display = flag ? 'block' : 'none';
             cookieTool.setCookie(id, display, 10);
         } else {
             cookieTool.setCookie(id, id, 10);
             var curId = cookieTool.getCookie(id);
             $('.treemenu').find('.on').removeClass('on').addClass('off');
             $('#' + curId).addClass('on');
             $('.treemenu a[class="off"]').each(function() {
                 cookieTool.delCookie($(this).attr('id')); //删除其他已选择选项cookie
             });
         }
     });

页面加载时重新设置菜单

 //页面加载读取cookies
     $('.treemenu a').each(function() {
         showMenu($(this).attr('id'));
     });

 //读取cookie显示菜单
 function showMenu(id) {
     var $this = $('#' + id);
     var cookie = cookieTool.getCookie(id);
     if (cookie) {
         if ($this.next('.submenu').length > 0) {
             $this.next('.submenu').css('display', cookie);
         } else {
             $('#' + cookie).addClass('on');
         }
     }
 }

完整DEMO：

【JavaScript】刷新不变化树形菜单(多级菜单).zip

注意：chrome本地控制台无法读取cookie，需要在firefox/IE或者服务器环境下测试