//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;

        }