//返回ipv 地址        public static string GetIP4Address()        {            string IP4Address = String.Empty;            foreach (IPAddress IPA in Dns.GetHostAddresses(HttpContext.Current.Request.UserHostAddress))            {                if (IPA.AddressFamily.ToString() == "InterNetwork")                {                    IP4Address = IPA.ToString();                    break;                }            }            if (IP4Address != String.Empty)            {                return IP4Address;            }            foreach (IPAddress IPA in Dns.GetHostAddresses(Dns.GetHostName()))            {                if (IPA.AddressFamily.ToString() == "InterNetwork")                {                    IP4Address = IPA.ToString();                    break;                }            }            return IP4Address;        }