获得客户端外网IP地址

#region 获得客户端外网IP地址
        /// <summary>
        /// 获得客户端外网IP地址
        /// </summary>
        /// <returns>IP地址</returns>
        public static string GetClientInternetIP()
        {
            string ipAddress = "";
            using (WebClient webClient = new WebClient())
            {
                try
                {
                    ipAddress = webClient.DownloadString("http://www.ip138.com/ip2city.asp");//站获得IP的网页
                    Regex myRegex = new Regex(@"(\d{1,3}(\.\d{1,3}){3})", RegexOptions.IgnoreCase);
                    ipAddress = myRegex.Match(ipAddress).Groups[1].Value;
                    //判断IP是否合法
                    if (!System.Text.RegularExpressions.Regex.IsMatch(ipAddress, "[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}"))
                    {
                        ipAddress = webClient.DownloadString("http://www.zu14.cn/ip/");//站获得IP的网页
                    }
                }
                catch (Exception)
                {
                }
                
            }
            return ipAddress;
        }
        #endregion

 string _LANip = "";//本地IP

            
            System.Net.IPHostEntry ipHost = System.Net.Dns.GetHostEntry(System.Net.Dns.GetHostName()); ;
            System.Net.IPAddress ipaddress = ipHost.AddressList[0];
            _LANip = ipaddress.ToString();