获取IP

public static string GetIP()
        {

            string result = String.Empty;

            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;
            }

            if (null == result || result == String.Empty || !IsIP(result))
            {
                return "0.0.0.0";
            }

            return result;

        }

public static bool IsIP(string ip)
        {
            return Regex.IsMatch(ip, @"^((2[0-4]\d|25[0-5]|[01]?\d\d?)\.){3}(2[0-4]\d|25[0-5]|[01]?\d\d?)$");

        }