public function index()
 {
     $this->checklogin();
     //检查是否登录了
     $this->assign("admin", session("username"));
     //设置登录验证
     //$this->assign("lasttime",session("lasttime"));
     //$this->assign("username",session("username"));
     //$this->assign("count",session("count"));//显示登录次数
     $theme = C(readconf::get_theme());
     //获取主题名->对应的主题文件夹名
     $this->assign("theme", $theme);
     switch ($_SESSION["role"]) {
         case 1:
             $this->assign("menu", $this->menu());
             break;
         case 2:
             $this->assign("menu", $this->teachermenu());
             break;
         case 3:
             $this->assign("menu", $this->mastermenu());
             break;
         default:
             $this->assign("menu", $this->stumenu());
             break;
     }
     $theme = C(readconf::get_theme());
     //获取主题名->对应的主题文件夹名
     $this->assign("theme", $theme);
     $s = M("notice")->order('id desc')->limit(10)->select();
     $this->assign("notice_list", $s);
     $this->display();
 }