获取客户端真实IP

       #region 获取客户端真实IP
        public static string ClientIP(this Controller ctrl)
        {
            string userip = "";
            // 如果客户端用了代理服务器，则应该用ServerVariables("HTTP_X_FORWARDED_FOR")方法
            if (ctrl.HttpContext.Request.ServerVariables["HTTP_X_FORWARDED_FOR"] != null)
                userip = ctrl.HttpContext.Request.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString();
            // 如果客户端没用代理，应该用Request.ServerVariables("REMOTE_ADDR")方法
            if (userip.Length == 0)
                userip = ctrl.HttpContext.Request.ServerVariables["REMOTE_ADDR"].ToString();
            return userip;
        }
        #endregion