c# 获得内外网IP地址

///获取本地ip地址,优先取内网ip

public static String GetLocalIp()
        {
            String[] Ips = GetLocalIpAddress();
            foreach (String ip in Ips) if (ip.StartsWith("10.80.")) return ip;
            foreach (String ip in Ips) if (ip.Contains(".")) return ip;
            return "127.0.0.1";
        }

///获取本地ip地址,多个ip

  public static String[] GetLocalIpAddress()
        {
            string hostName = Dns.GetHostName();                    //获取主机名称    
            IPAddress[] addresses = Dns.GetHostAddresses(hostName); //解析主机IP地址    
            string[] IP = new string[addresses.Length];             //转换为字符串形式    
            for (int i = 0; i < addresses.Length; i++) IP[i] = addresses[i].ToString();
            return IP;
        }

 

///获取外网ip地址

   public static string GetExtranetIpAddress2()
        {
            string IP = "127.0.0.1";
            try
            {
                //从网址中获取本机ip数据    
                System.Net.WebClient client = new System.Net.WebClient();
                client.Encoding = System.Text.Encoding.Default;
                string str = client.DownloadString("http://1111.ip138.com/ic.asp");
                client.Dispose();
                //提取外网ip数据 [218.104.71.178]    
                int i1 = str.IndexOf("["), i2 = str.IndexOf("]");
                IP = str.Substring(i1 + 1, i2 - 1 - i1);
            }
            catch (Exception) { }
            return IP;
        }

///获取外网ip地址

 public static string GetExtranetIpAddress()
        {
            String url = "http://hijoyusers.joymeng.com:8100/test/getNameByOtherIp";
            string IP = "127.0.0.1";
            try
            {
                //从网址中获取本机ip数据    
                System.Net.WebClient client = new System.Net.WebClient();
                client.Encoding = System.Text.Encoding.Default;
                string str = client.DownloadString(url);
                client.Dispose();
                if (!str.Equals("")) IP = str;
                else IP = GetExtranetIpAddress2();
            }
            catch (Exception) { }
            return IP;
        }