C# WINFORM获取计算机本机对外IP地址

        /// <summary>
        /// 获取对外IP地址
        /// </summary>
        /// <returns></returns>
        public static string GetIP()
        {
            using (var webClient = new WebClient())
            {
                try
                {
                    var temp = webClient.DownloadString("http://1111.ip138.com/ic.asp");
                    var ip = Regex.Match(temp, @"\[(?<ip>\d+\.\d+\.\d+\.\d+)]").Groups["ip"].Value;
                    return !string.IsNullOrEmpty(ip) ? ip : null;
                }
                catch (Exception ex)
                {
                    return ex.Message;
                }
            }
        }