///<summary>
        /// 当前用户信息
        ///</summary>
        public SitePrincipal CurrentUser
        {
            get
            {
                SiteIdentity siteIdentity = null;
                SitePrincipal sitePrincipal = System.Web.HttpContext.Current.Session["UserInfo"] as SitePrincipal;
                if (sitePrincipal != null)
                {
                    siteIdentity = sitePrincipal.Identity as SiteIdentity;
                }

                if (siteIdentity == null)
                {
                    return new SitePrincipal ();
                }
                return siteIdentity;
            }
        }