P2P之UDP穿透NAT的原理与C#实现

namespace P2P.P2PClient
{

    using System;

    using System.Net;

    using System.Net.Sockets;

    using System.Threading;

    using P2P.WellKnown;

    /// 


    /// AppClass 的摘要说明。

    /// 


    public class AppClass
    {

        public static void Main（）
        {

            Client client = new Client（“192.168.1.25“）;

            client.ConnectToServer（“myname1“ “mypassword1“）;

            client.Start（）;

            Console.WriteLine（“test arguments“）;

            while （true）
            {

                string str = Console.ReadLine（）;

                client.PaserCommand（str）;

            }

        }

    }

    /// 


    /// Client 的摘要说明。

    /// 


    public class Client : IDisposable
    {

        private const int MAXRETRY = 10;

        private UdpClient client;

        private IPEndPoint hostPoint;

        private IPEndPoint remotePoint;

        private UserCollection userList;

        private string myName;

        private bool ReceivedACK;

        private Thread listenThread;



        public Client（string serverIP）
        {

            ReceivedACK = false;

            remotePoint = new IPEndPoint（IPAddress.Any 0）;

            hostPoint = new IPEndPoint（IPAddress.Parse（serverIP） P2PConsts.SRV_PORT）;

            client = new UdpClient（）;

            userList = new UserCollection（）;

            listenThread = new Thread（new ThreadStart（Run））;

        }



        public void Start（）
        {

            if （this.listenThread.ThreadState == ThreadState.Unstarted）
            {

                this.listenThread.Start（）;

                Console.WriteLine（“You can input you command:\n“）;

                Console.WriteLine（“Command Type:\“send\“\“exit\“\“getu\““）;

                Console.WriteLine（“Example : send Username Message“）;

                Console.WriteLine（“          exit“）;

                Console.WriteLine（“          getu“）;

            }

        }



        public void ConnectToServer（string userName string password）
        {

            myName = userName;

            // 发送登录消息到服务器

            P2P.WellKnown.C2S.LoginMessage lginMsg = new P2P.WellKnown.C2S.LoginMessage（userName password）;

            byte[] buffer = FormatterHelper.Serialize（lginMsg）;

            client.Send（buffer buffer.Length hostPoint）;

            // 接受服务器的登录应答消息

            buffer = client.Receive（ref remotePoint）;

            P2P.WellKnown.S2C.GetUsersResponseMessage srvResMsg = （P2P.WellKnown.S2C.GetUsersResponseMessage）FormatterHelper.Deserialize（buffer）;

            // 更新用户列表

            userList.Clear（）;

            foreach （User user in srvResMsg.UserList）
            {

                userList.Add（user）;

            }

            this.DisplayUsers（userList）;

        }



        ///