Lấy IP ra Internet của máy đằng client

using System;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;

namespace DreamInCode.Snippets
{
public class IpFinder
{
public static IPAddress GetExternalIp()
{
string whatIsMyIp = "http://whatismyip.com";
string getIpRegex = @"(?<=<TITLE>.*)\d*\.\d*\.\d*\.\d*(?=<TITLE>)";
WebClient wc = new WebClient();
UTF8Encoding utf8 = new UTF8Encoding();
string requestHtml = "";
try
{
requestHtml = utf8.GetString(wc.DownloadData(whatIsMyIp));
}
catch (WebException we)
{
// do something with exception
Console.Write(we.ToString());
}
Regex r = new Regex(getIpRegex);
Match m = r.Match(requestHtml);
IPAddress externalIp = null;
if (m.Success)
{
externalIp = IPAddress.Parse(m.Value);
}
return externalIp;
}
}
}