IP地址工具类

  /// <summary>

        /// 获取客户端IP地址

        /// </summary>

        /// <returns></returns>

        public static string GetHostAddress()

        {

            string userHostAddress = HttpContext.Current.Request.UserHostAddress;

            if (string.IsNullOrEmpty(userHostAddress))

            {

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

            }

            //最后判断获取是否成功，并检查IP地址的格式（检查其格式非常重要）

            if (!string.IsNullOrEmpty(userHostAddress) && IsIP(userHostAddress))

            {

                return userHostAddress;

            }

            return "127.0.0.1";

        }

        public static bool IsIP(string ip)

        {

            return System.Text.RegularExpressions.Regex.IsMatch(ip, @"^((2[0-4]\d|25[0-5]|[01]?\d\d?)\.){3}(2[0-4]\d|25[0-5]|[01]?\d\d?)$");

        }