/// <summary>

         /// 得到当前网站的根地址

         /// </summary>

         /// <returns></returns>

         protected string GetRootPath()

         {

             // 是否为SSL认证站点

             string secure = HttpContext.Current.Request.ServerVariables["HTTPS"];

             string httpProtocol = (secure == "on" ? "https://" : "http://");

             // 服务器名称

             string serverName = HttpContext.Current.Request.ServerVariables["Server_Name"];

             string port = HttpContext.Current.Request.ServerVariables["SERVER_PORT"];

             // 应用服务名称

             string applicationName = HttpContext.Current.Request.ApplicationPath;

             return httpProtocol + serverName + (port.Length >  ? ":" + port : string.Empty) + applicationName;

         }