获取真实的客户端IP地址

 /// <summary>
        ///  通过代理，获取真实的客户端IP地址
        /// </summary>
        /// <returns></returns>
        protected string GetClientIPAddress()
        {
            try
            {
                string result = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

                if (null == result || result == String.Empty)
                {

                    result = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];

                }

 

                if (null == result || result == String.Empty)
                {

                    result = HttpContext.Current.Request.UserHostAddress;

                }

                return result;
            }
            catch
            {
                return string.Empty;
            }
        }