/// <summary>        /// 获得请求的ip        /// </summary>        /// <returns></returns>        public static string GetIP()        {            string ip = string.Empty;            if (HttpContext.Current.Request.ServerVariables["HTTP_VIA"] != null)                ip = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString();            else                ip = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"].ToString();            if (string.IsNullOrEmpty(ip) || !ValidateHelper.IsIP(ip))                ip = "127.0.0.1";            return ip;        }

  /// <summary>        /// 是否为IP        /// </summary>        public static bool IsIP(string s)        {            return _ipregex.IsMatch(s);        } //IP正则表达式        private static Regex _ipregex = new Regex(@"^(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])\.(\d{1,2}|1\d\d|2[0-4]\d|25[0-5])$");