获取公网IP地址

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
string ip = GetClientInternetIP();
Console.WriteLine(ip);
Console.Read();
}

/// <summary>
/// 获得客户端外网IP地址
/// </summary>
/// <returns>IP地址</returns>
public static string GetClientInternetIP()
{
string ip;
using (WebClient webClient = new WebClient())
{
var content = webClient.DownloadString("http://1212.ip138.com/ic.asp"); //站获得IP的网页
//判断IP是否合法
ip = new Regex(@"\[((\d{1,3}\.){3}\d{1,3})\]").Match(content).Groups[1].Value;
}
return ip;
}

//如果是ADSL上网，获取公网ip
public static string GetADSL_Ip()
{
string tempIP = string.Empty;
if (System.Net.Dns.GetHostEntry(System.Net.Dns.GetHostName()).AddressList.Length > 1)
tempIP = System.Net.Dns.GetHostEntry(System.Net.Dns.GetHostName()).AddressList[1].ToString();
return tempIP;
}
}
}