局域网QQ（C#版）

        本通讯程序没有服务端和客户端之分，局域网的计算机运行同一程序即可通信。
由于水平有限，目前版本还很菜，只可以实现基本的聊天功能和显示在线用户功能。
准备添加传送文件、聊天日志、可选参数等功能。

using System; using System.Drawing; using System.Collections; using System.ComponentModel; using System.Windows.Forms; using System.Data; using System.Net; using System.Net.Sockets; using System.Text; using System.Threading; namespace myQQ {  /// <summary>  /// Form1 的摘要说明。  /// </summary>  public class Form1 : System.Windows.Forms.Form  {   public bool runing=false; //标志   public UdpClient listen=new UdpClient(2525);   public IPEndPoint End;   public IPAddress groupAddress=IPAddress.Parse("255.255.255.255"); //广播地址   public int groupPort=2525;  //广播端口   public string machineName;   public string machineIP;   public string romeName;   public string romeIP;   public string romeCon;     private System.Windows.Forms.ListBox box;   private System.Windows.Forms.Label label1;   private System.Windows.Forms.Label label2;   private System.Windows.Forms.Button button1;   private System.Windows.Forms.Button button3;   private System.Windows.Forms.Label label3;   private System.Windows.Forms.TextBox t_rec;   private System.Windows.Forms.TextBox t_send;   private System.Windows.Forms.Button button2;   private System.Windows.Forms.Button newmsg;   /// <summary>   /// 必需的设计器变量。   /// </summary>   private System.ComponentModel.Container components = null;   public Form1()   {    //    // Windows 窗体设计器支持所必需的    //    InitializeComponent();    //    // TODO: 在 InitializeComponent 调用后添加任何构造函数代码    //   }   /// <summary>   /// 清理所有正在使用的资源。   /// </summary>   protected override void Dispose( bool disposing )   {    if( disposing )    {     if (components != null)     {      components.Dispose();     }    }    base.Dispose( disposing );   }   #region Windows 窗体设计器生成的代码   /// <summary>   /// 设计器支持所需的方法 - 不要使用代码编辑器修改   /// 此方法的内容。   /// </summary>   private void InitializeComponent()   {    this.box = new System.Windows.Forms.ListBox();    this.t_rec = new System.Windows.Forms.TextBox();    this.label1 = new System.Windows.Forms.Label();    this.label2 = new System.Windows.Forms.Label();    this.t_send = new System.Windows.Forms.TextBox();    this.button1 = new System.Windows.Forms.Button();    this.button3 = new System.Windows.Forms.Button();    this.label3 = new System.Windows.Forms.Label();    this.button2 = new System.Windows.Forms.Button();    this.newmsg = new System.Windows.Forms.Button();    this.SuspendLayout();    //    // box    //    this.box.ItemHeight = 12;    this.box.Location = new System.Drawing.Point(0, 32);    this.box.Name = "box";    this.box.Size = new System.Drawing.Size(200, 352);    this.box.TabIndex = 0;    //    // t_rec    //    this.t_rec.BackColor = System.Drawing.SystemColors.InactiveBorder;    this.t_rec.ForeColor = System.Drawing.Color.FromArgb(((System.Byte)(192)), ((System.Byte)(64)), ((System.Byte)(0)));    this.t_rec.Location = new System.Drawing.Point(208, 56);    this.t_rec.Multiline = true;    this.t_rec.Name = "t_rec";    this.t_rec.ScrollBars = System.Windows.Forms.ScrollBars.Vertical;    this.t_rec.Size = new System.Drawing.Size(328, 136);    this.t_rec.TabIndex = 1;    this.t_rec.Text = "";    //    // label1    //    this.label1.Location = new System.Drawing.Point(208, 40);    this.label1.Name = "label1";    this.label1.Size = new System.Drawing.Size(120, 16);    this.label1.TabIndex = 2;    this.label1.Text = "接收：";    //    // label2    //    this.label2.Location = new System.Drawing.Point(208, 200);    this.label2.Name = "label2";    this.label2.Size = new System.Drawing.Size(120, 16);    this.label2.TabIndex = 2;    this.label2.Text = "发送：";    //    // t_send    //    this.t_send.Location = new System.Drawing.Point(208, 216);    this.t_send.Multiline = true;    this.t_send.Name = "t_send";    this.t_send.ScrollBars = System.Windows.Forms.ScrollBars.Vertical;    this.t_send.Size = new System.Drawing.Size(328, 112);    this.t_send.TabIndex = 1;    this.t_send.Text = "";    //    // button1    //    this.button1.Location = new System.Drawing.Point(440, 344);    this.button1.Name = "button1";    this.button1.Size = new System.Drawing.Size(75, 32);    this.button1.TabIndex = 3;    this.button1.Text = "发  送";    this.button1.Click += new System.EventHandler(this.button1_Click);    //    // button3    //    this.button3.FlatStyle = System.Windows.Forms.FlatStyle.Popup;    this.button3.Location = new System.Drawing.Point(88, 3);    this.button3.Name = "button3";    this.button3.Size = new System.Drawing.Size(56, 23);    this.button3.TabIndex = 4;    this.button3.Text = "刷 新";    this.button3.Click += new System.EventHandler(this.button3_Click);    //    // label3    //    this.label3.Font = new System.Drawing.Font("宋体", 9F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(134)));    this.label3.ForeColor = System.Drawing.Color.Blue;    this.label3.Location = new System.Drawing.Point(8, 8);    this.label3.Name = "label3";    this.label3.Size = new System.Drawing.Size(80, 16);    this.label3.TabIndex = 5;    this.label3.Text = "在线用户：";    //    // button2    //    this.button2.Location = new System.Drawing.Point(360, 344);    this.button2.Name = "button2";    this.button2.Size = new System.Drawing.Size(75, 32);    this.button2.TabIndex = 6;    this.button2.Text = "清  空";    this.button2.Click += new System.EventHandler(this.button2_Click);    //    // newmsg    //    this.newmsg.Location = new System.Drawing.Point(208, 56);    this.newmsg.Name = "newmsg";    this.newmsg.Size = new System.Drawing.Size(328, 136);    this.newmsg.TabIndex = 7;    this.newmsg.Text = "有新消息了！";    this.newmsg.Click += new System.EventHandler(this.newmsg_Click);    //    // Form1    //    this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);    this.ClientSize = new System.Drawing.Size(544, 389);    this.Controls.Add(this.button2);    this.Controls.Add(this.label3);    this.Controls.Add(this.button3);    this.Controls.Add(this.button1);    this.Controls.Add(this.label1);    this.Controls.Add(this.box);    this.Controls.Add(this.label2);    this.Controls.Add(this.t_send);    this.Controls.Add(this.t_rec);    this.Controls.Add(this.newmsg);    this.Name = "Form1";    this.Text = "小y";    this.Closing += new System.ComponentModel.CancelEventHandler(this.Form1_Closing);    this.Load += new System.EventHandler(this.Form1_Load);    this.ResumeLayout(false);   }   #endregion   /// <summary>   /// 应用程序的主入口点。   /// </summary>   [STAThread]   static void Main()   {    Application.Run(new Form1());   }   private void Form1_Load(object sender, System.EventArgs e)   {          End=new IPEndPoint(groupAddress,groupPort);    //初始化计算机名和端口    IPHostEntry myentry=Dns.GetHostByName(Dns.GetHostName());    IPAddress myaddress=new IPAddress(myentry.AddressList[0].Address);    machineName=Dns.GetHostName();    machineIP=myaddress.ToString();    box.Items.Add("IP            主机名");    //开启监听线程    runing=true;    Thread myThread=new Thread(new ThreadStart(this.ListenPort));    myThread.Start();    //发送上线信息    string sends="0&"+machineIP+"&"+machineName+"&"+machineIP;    SendPack(sends);   }   //侦听指定端口的广播地址UDP包   public void ListenPort()   {    IPEndPoint tempEnd=new IPEndPoint(IPAddress.Any,2525);    while(runing)    {     Application.DoEvents();     try     {      byte[] recb=listen.Receive(ref tempEnd);      // 检查所接收到的信息      checkMessage(recb);     }     catch(Exception e)     {      MessageBox.Show(e.Message.ToString());      break;     }        }    listen.Close();    box.Items.Add("线程已经退出！");    runing=false;   }   //循环接收包   public void checkMessage(byte[] recbb)   {    string recStr=Encoding.Default.GetString(recbb);    string[] rec=recStr.Split('&');    switch(rec[0])    {     case "0": //刷新      if(rec[3]==machineIP)      {       if(box.FindString(rec[1]+"  "+rec[2])<=0)            box.Items.Add(rec[1]+"  "+rec[2]);      }      else  if(rec[1]==rec[3])      {       //从其他机器发送过来的刷新请求       //返回自己的信息       string sendstr="0&"+machineIP+"&"+machineName+"&"+rec[3];       this.SendPack(sendstr);       //如果不存在则添加该用户       if(box.FindString(rec[1]+"  "+rec[2])<=0)        box.Items.Add(rec[1]+"  "+rec[2]);      }      break;     case "1": //发言      if(rec[3]==machineIP)      {       romeName=rec[2];       romeIP=rec[1];       romeCon=rec[4];       showNe();      }      break;     case "2": //传文件      break;     case "9": //确认包      if(rec[3]==machineIP)       MessageBox.Show("信息来自：rec[2]("+rec[1]+")\r\n"+rec[4],"消息");      break;    }      }          //发送数据包到广播地址   public void SendPack(string sendStr)   {       byte[] sendb=Encoding.Default.GetBytes(sendStr);    try    {     listen.Send(sendb,sendb.Length,End);    }    catch(Exception e)    {     MessageBox.Show(e.Message.ToString());    }   }   //刷新   private void button3_Click(object sender, System.EventArgs e)   {    box.Items.Clear();    box.Items.Add("IP            主机名");    string temp2="0&"+machineIP+"&"+machineName+"&"+machineIP;    this.SendPack(temp2);   }   //关闭循环   private void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)   {    runing=false;    UdpClient mm=new UdpClient();    IPEndPoint tempIPEnd=new IPEndPoint(IPAddress.Parse("127.0.0.1"),2525);    string temps="0&0&0&0&0";    byte[] sendb=Encoding.Default.GetBytes(temps);    mm.Send(sendb,sendb.Length,tempIPEnd);   }   //发送   private void button1_Click(object sender, System.EventArgs e)   {    if(t_send.Text=="")    {     MessageBox.Show("不能发送空信息！");     return;    }    if(box.SelectedItem==null||box.SelectedIndex==0)    {     MessageBox.Show("请先选择一个用户！");     return;    }    string send="1&"+machineIP+"&"+machineName+"&"+box.SelectedItem.ToString().Split(' ')[0]+"&"+t_send.Text;    this.SendPack(send);   }   //清空   private void button2_Click(object sender, System.EventArgs e)   {    t_send.Text=string.Empty;    t_rec.Text=string.Empty;   }   //单击显示接收的信息并隐藏自身   private void newmsg_Click(object sender, System.EventArgs e)   {    t_rec.Text="消息来自"+romeName+"("+romeIP+")"+DateTime.Now.ToShortDateString();    t_rec.Text+="\r\n> "+romeCon;    string back="9&"+machineIP+"&"+machineName+"&"+romeIP+"&信息被打开！";    this.SendPack(back);    newmsg.SendToBack();   }   //当有信息时显示提示按钮   public void showNe()   {    //窗体显示    if(this.WindowState!=FormWindowState.Normal)    {     this.Visible=true;     this.WindowState=FormWindowState.Normal;    }    newmsg.BringToFront();   }  } }