C#编写的基于UDP的多人聊天系统

用C#写的基于UDP的聊天系统，能实现多台电脑聊天，没有服务器

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Net;
using System.Threading;

namespace UdpChatExample
{
    public partial class FormMain : Form
    {
        /// 

        /// 接收用
        /// 

        private UdpClient receiveUdpClient;
        /// 

        /// 发送用
        /// 

        private UdpClient sendUdpClient;
        /// 

        /// 和本机绑定的端口号
        /// 

        private const int port = 8889;
        /// 

        /// 本机IP
        /// 

        IPAddress ip;
        /// 

        /// 远程主机IP
        /// 

        IPAddress remoteIp;
        public FormMain（）
        {
            InitializeComponent（）;
            //获取本机可用IP地址
            IPAddress[] ips = Dns.GetHostAddresses（Dns.GetHostName（））;
            foreach （IPAddress ipa in ips）
            {
                if （ipa.AddressFamily == AddressFamily.InterNetwork）
                {
                    ip = ipa;
                    break;
                }
            }
            //为了在同一台机器调试，此IP也作为默认远程IP
            remoteIp = ip;
            txt_IPAddress.Text = remoteIp.ToString（）;
            txt_Send.Text = “你好！“;
        }

        private void FormMain_Load（object sender EventArgs e）
        {
            //创建一个县城接收远程主机发来的信息
            Thread myThread = new Thread（ReceiveData）;
            myThread.IsBackground = true;
            myThread.Start（）;
            txt_Send.Focus（）;
        }

        /// 

        /// 接收数据
        /// 

        private void ReceiveData（）
        {
            IPEndPoint local = new IPEndPoint（ip port）;
            receiveUdpClient = new UdpClient（local）;
            IPEndPoint remote = new IPEndPoint（IPAddress.Any 0）;
            while （true）
            {
                try
                {
                    //关闭udpClient 时此句会产生异常
                    byte[] receiveBytes = receiveUdpClient.Receive（ref remote）;
                    string receiveMessage = Encoding.Unicode.GetString（
                        receiveBytes 0 receiveBytes.Length）;
                    AddItem（lst_Receive string.Format（“来自{0}:{1}“ remote receiveMessage））;
                }
                catch
                {
                    break;
                }
            }
        }

        private void button1_Click（object sender EventArgs e）
        {
            remoteIp = IPAddress.Parse（txt_IPAddress.Text）;
            Thread myThread = new Thread（SendMessage）;
            myThread.IsBackground = true;
            myThread.Start（txt_Send.Text）;
        }

        /// 

        /// 发送消息
        /// 

        /// 
        private void

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----

     文件       4745  2011-08-09 03:08  UdpChatExample\UdpChatExample\Backup\FormMain.cs

     文件       6781  2011-08-09 02:02  UdpChatExample\UdpChatExample\Backup\FormMain.Designer.cs

     文件       5814  2011-08-09 02:02  UdpChatExample\UdpChatExample\Backup\FormMain.resx

     文件        498  2011-08-09 01:49  UdpChatExample\UdpChatExample\Backup\Program.cs

     文件       1378  2011-08-09 01:41  UdpChatExample\UdpChatExample\Backup\Properties\AssemblyInfo.cs

     文件       2878  2011-08-09 01:41  UdpChatExample\UdpChatExample\Backup\Properties\Resources.Designer.cs

     文件       5612  2011-08-09 01:41  UdpChatExample\UdpChatExample\Backup\Properties\Resources.resx

     文件       1099  2011-08-09 01:41  UdpChatExample\UdpChatExample\Backup\Properties\Settings.Designer.cs

     文件        249  2011-08-09 01:41  UdpChatExample\UdpChatExample\Backup\Properties\Settings.settings

     文件       3754  2011-08-09 02:09  UdpChatExample\UdpChatExample\Backup\UdpChatExample.csproj

     文件      12288  2015-06-30 16:06  UdpChatExample\UdpChatExample\bin\Debug\UdpChatExample.exe

     文件      30208  2015-06-30 16:06  UdpChatExample\UdpChatExample\bin\Debug\UdpChatExample.pdb

     文件      11608  2015-06-30 16:06  UdpChatExample\UdpChatExample\bin\Debug\UdpChatExample.vshost.exe

     文件        490  2010-03-17 22:39  UdpChatExample\UdpChatExample\bin\Debug\UdpChatExample.vshost.exe.manifest

     文件      16553  2011-08-09 02:55  UdpChatExample\UdpChatExample\bin\Debug.rar

     文件       4745  2011-08-09 03:08  UdpChatExample\UdpChatExample\FormMain.cs

     文件       6781  2011-08-09 02:02  UdpChatExample\UdpChatExample\FormMain.Designer.cs

     文件       5814  2011-08-09 02:02  UdpChatExample\UdpChatExample\FormMain.resx

     文件       6055  2015-06-30 16:08  UdpChatExample\UdpChatExample\obj\Debug\DesignTimeResolveAssemblyReferencesInput.cache

     文件        722  2015-06-30 16:06  UdpChatExample\UdpChatExample\obj\Debug\GenerateResource-ResGen.read.1.tlog

     文件        658  2015-06-30 16:06  UdpChatExample\UdpChatExample\obj\Debug\GenerateResource-ResGen.write.1.tlog

     文件       4608  2015-06-30 16:06  UdpChatExample\UdpChatExample\obj\Debug\TempPE\Properties.Resources.Designer.cs.dll

     文件       1509  2015-06-30 16:13  UdpChatExample\UdpChatExample\obj\Debug\UdpChatExample.csproj.FileListAbsolute.txt

     文件        850  2011-08-09 02:09  UdpChatExample\UdpChatExample\obj\Debug\UdpChatExample.csproj.GenerateResource.Cache

     文件      12288  2015-06-30 16:06  UdpChatExample\UdpChatExample\obj\Debug\UdpChatExample.exe

     文件        180  2015-06-30 16:06  UdpChatExample\UdpChatExample\obj\Debug\UdpChatExample.FormMain.resources

     文件      30208  2015-06-30 16:06  UdpChatExample\UdpChatExample\obj\Debug\UdpChatExample.pdb

     文件        180  2015-06-30 16:06  UdpChatExample\UdpChatExample\obj\Debug\UdpChatExample.Properties.Resources.resources

     文件        498  2011-08-09 01:49  UdpChatExample\UdpChatExample\Program.cs

     文件       1378  2011-08-09 01:41  UdpChatExample\UdpChatExample\Properties\AssemblyInfo.cs

............此处省略26个文件信息