C#聊天程序服务端与客户端完整实例代码

本文所述为基于c#实现的多人聊天程序服务端与客户端完整代码。本实例省略了结构定义部分，服务端主要是逻辑处理部分代码，因此使用时需要完善一些窗体按钮之类的。

先看服务端代码如下：

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.threading;
namespace 多人聊天程序server端
{
 /// <summary>
 /// 应用程序的主入口点。
 /// </summary>
 [stathread]
 static void main()
 {
  application.run(new form1());
 }
 // 启动服务按钮
 private void button2_click(object sender, system.eventargs e)
 {
  try
  {
  // 必须填写端口
  if(txtport.text == "")
  {
   messagebox.show("请先填写服务端口号!", "提示");
   return;
  }
  int32 port = int32.parse(txtport.text); // 获得端口号
  // 创建侦听的socket
  mainsocket = new socket(addressfamily.internetwork, sockettype.stream, protocoltype.tcp);
  ipendpoint localep = new ipendpoint(ipaddress.any, port);
  // 将 socket 绑定到本地的终结点上
  mainsocket.bind(localep);
  // 开始侦听，最大的连接数是 5
  mainsocket.listen(5);
  // 开始一个异步操作接受客户的连接请求
  mainsocket.beginaccept(new asynccallback(onclientconnect), null);
  // 启动服务按钮不可用，停止服务按钮可用
  updatecontrols(true);
  }
  catch(socketexception se)
  {
  messagebox.show(se.message, "提示");
  }
 }
 // 更新“启动服务按钮”和“停止服务”按钮的状态：是否可用；
 // 注意：两个按钮的状态是互斥的
 private void updatecontrols(bool onserve)
 {
  button2.enabled = !onserve;
  button3.enabled = onserve;
  if(onserve)
  {
  status.text = "已启动服务";
  }
  else
  {
  status.text = "未启动服务";
  }
 }
 // 回调函数，当客户连接上时，将会被调用
 public void onclientconnect(iasyncresult asyn)
 {
  try
  {
  // 调用endaccept完成beginaccept异步调用，返回一个新的socket处理与客户的通信
  socket workersocket = mainsocket.endaccept(asyn);
  // 增加客户数目
  interlocked.increment(ref clientnum);
  // 将 workersocket socket加入到 arraylist 中
  workersocketlist.add(workersocket);
  // 发送欢迎信息给连接上服务器的客户
  string msg = "欢迎客户 " + clientnum + " 登录服务器\n";
  sendwelcometoclient(msg, clientnum);
  // 在线客户数目改变，必须更新客户列表
  updateclientlistcontrol();
  // 连接上的客户接收数据
  waitfordata(workersocket, clientnum);
  // 主 socket 返回，继续等待其它的连接请求
  mainsocket.beginaccept(new asynccallback(onclientconnect), null);
  }
  catch(objectdisposedexception)
  {
  system.diagnostics.debugger.log(0,"1","\n onclientconnection: socket已经关闭!\n");
  }
  catch(socketexception se)
  {
  messagebox.show(se.message, "提示");
  }
 }
 // 发送欢迎信息给客户
 void sendwelcometoclient(string msg, int clientnumber)
 {
  // 用utf8格式来将string信息转化成byte数组形式
  byte[] bydata = system.text.encoding.utf8.getbytes(msg);
  // 获得客户clientnumber对应的socket
  socket workersocket = (socket)workersocketlist[clientnumber - 1];
  // 将数据发给客户
  workersocket.send(bydata);
 }
 // 该类保存当前的socket，它的客户号还有发送给服务器的数据
 public class socketpacket
 {
  public system.net.sockets.socket currentsocket; // 当前的socket
  public int clientnumber; // 客户号
  public byte[] databuffer = new byte[1024]; // 发给服务器的数据
  // 构造函数
  public socketpacket(system.net.sockets.socket socket, int clientnumber)
  {
  currentsocket = socket;
  this.clientnumber = clientnumber;
  }
 }
 // 开始等待客户发送数据
 public void waitfordata(system.net.sockets.socket socket, int clientnumber)
 {
  try
  {
  if(pfnworkercallback == null)
  {
   // 当连接上的客户有写的操作的时候，调用回调函数
   pfnworkercallback = new asynccallback(ondatareceived);
  }
  socketpacket socketpacket = new socketpacket(socket, clientnumber);
  socket.beginreceive(socketpacket.databuffer, 0, socketpacket.databuffer.length,
            socketflags.none, pfnworkercallback, socketpacket);
  }
  catch(socketexception se)
  {
  messagebox.show (se.message, "提示");
  }
 }
 // 当客户写数据时，调用以下方法
 public void ondatareceived(iasyncresult asyn)
 {
  socketpacket socketdata = (socketpacket)asyn.asyncstate ;
  try
  {
  // endreceive完成beginreceive异步调用，返回客户写入流的字节数
  int irx = socketdata.currentsocket.endreceive(asyn);
  // 加 1 是因为字符串以 '\0' 作为结束标志符
  char[] chars = new char[irx + 1];
  // 对客户发来的信息进行utf8解码，存入chars字符数组中
  system.text.decoder decoder = system.text.encoding.utf8.getdecoder();
  int charlen = decoder.getchars(socketdata.databuffer, 0, irx, chars, 0);
  system.string szdata = new system.string(chars);
  string msg = "客户 " + socketdata.clientnumber + " 发的信息:" + szdata;
  // 将客户发的数据加入到信息列表中
  appendtoricheditcontrol(msg);
  // 等待数据
  waitfordata(socketdata.currentsocket, socketdata.clientnumber);
  }
  catch (objectdisposedexception )
  {
  system.diagnostics.debugger.log(0,"1","\nondatareceived: socket已经关闭!\n");
  }
  catch(socketexception se)
  {
  if(se.errorcode == 10054)
  {
   // 将客户断开连接的信息写入信息列表中
   string msg = "客户 " + socketdata.clientnumber + " 已断开了连接!" + "\n";
   appendtoricheditcontrol(msg);
   // 移走已关闭的socket
   workersocketlist[socketdata.clientnumber - 1] = null;
   // 更新客户列表
   updateclientlistcontrol();
  }
  else
  {
   messagebox.show (se.message, "提示");
  }
  }
 }
 // 更新信息列表，该方法可由主线程或其他工作线程所调用
 private void appendtoricheditcontrol(string msg)
 {
  // 测试看是哪个线程调用了该方法
  if (invokerequired)
  {
  // we cannot update the gui on this thread.
  // all gui controls are to be updated by the main (gui) thread.
  // hence we will use the invoke method on the control which will
  // be called when the main thread is free
  // do ui update on ui thread
  object[] plist = {msg};
  txtrecvmsg.begininvoke(new updatericheditcallback(onupdaterichedit), plist);
  }
  else
  {
  // 创建该控件的主线程直接更新信息列表
  onupdaterichedit(msg);
  }
 }
 // 添加信息到 txtrecvmsg 中
 private void onupdaterichedit(string msg)
 {
 // txtrecvmsg.appendtext(msg);
  txtrecvmsg.text = txtrecvmsg.text + msg;
 }
 // 更新客户列表
 private void updateclientlistcontrol()
 {
  if (invokerequired) // is this called from a thread other than the one created
  // the control
  {
  clientlist.begininvoke(new updateclientlistcallback(updateclientlist), null);
  }
  else
  {
  // 创建该控件的主线程直接更新信息列表
  updateclientlist();
  }
 }
 // 更新客户列表
 void updateclientlist()
 {
  clientlist.items.clear(); // 清空客户列表
  for(int i = 0; i < workersocketlist.count; i++)
  {
  // 加1，是因为数组从下标0开始，而我们的客户标号是从1开始
  string clientkey = convert.tostring(i + 1);
  socket workersocket = (socket)workersocketlist[i];
  if(workersocket != null)
  {
   // 将连接着服务器的客户添加到客户列表中
   if(workersocket.connected)
   {
   clientlist.items.add(clientkey);
   }
  }
  }
 }
 // 停止服务按钮
 private void button3_click(object sender, system.eventargs e)
 {
  closesockets();
  updatecontrols(false);
  // 更新客户列表
  updateclientlistcontrol();
 }
 // 发送信息按钮
 private void button1_click(object sender, system.eventargs e)
 {
  // 如果在线客户列表不为空，则允许发送信息
  if (clientlist.items.count != 0 )
  {
  try
  {
   string msg = txtsendmsg.text;
   msg = "服务器信息: " + msg + "\n";
   byte[] bydata = system.text.encoding.utf8.getbytes(msg);
   socket workersocket = null;
   for(int i = 0; i < workersocketlist.count; i++)
   {
   workersocket = (socket)workersocketlist[i];
   if(workersocket!= null)
   {
    // 发给所有连接上服务器的客户
    if(workersocket.connected)
    {
    workersocket.send(bydata);
    }
   }
   }
  }
  catch(socketexception se)
  {
   messagebox.show(se.message, "提示");
  }
  }
  else
  {
  messagebox.show("没有在线客户,不能发送信息!", "提示");
  }
 }
 // 清空信息按钮
 private void button4_click(object sender, system.eventargs e)
 {
  txtrecvmsg.clear(); // 清空从客户发来的信息
 }
 // 关闭窗体按钮
 private void button5_click(object sender, system.eventargs e)
 {
  closesockets();
  close();
 }
 // 关闭socket
 void closesockets()
 {
  // 关闭主socket
  if(mainsocket != null)
  {
  mainsocket.close();
  }
  socket workersocket = null;
  // 关闭客户 socket 数组
  for(int i = 0; i < workersocketlist.count; i++)
  {
  workersocket = (socket)workersocketlist[i];
  if(workersocket != null)
  {
   workersocket.close();
   workersocket = null;
  }
  }
 }
 private void form1_load(object sender, system.eventargs e)
 {
  try
  {
  // 获得本机的ip地址
  txtip.text = dns.resolve(dns.gethostname()).addresslist[0].tostring();
  // 启动时，启动服务按钮可用，停止服务按钮不可用
  updatecontrols(false);
  }
  catch(exception exc)
  {
  messagebox.show(exc.message, "提示");
  }
 }
 }
}

客户端主要实现接收来自服务端返回的消息、实现发送消息的操作界面，创建socket实例，得到服务器的ip地址，更新控件，连接和断开等，具体代码如下：

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;
namespace 多人聊天程序client端
{
 public class form1 : system.windows.forms.form
 {
 private system.windows.forms.label label1;
 private system.windows.forms.textbox txtip;
 private system.windows.forms.label label2;
 private system.windows.forms.label label3;
 private system.windows.forms.richtextbox txtsendmsg;
 private system.windows.forms.label label4;
 private system.windows.forms.button button1;
 private system.windows.forms.button button2;
 private system.windows.forms.button button3;
 private system.windows.forms.button button4;
 private system.windows.forms.richtextbox txtrecvmsg;
 private system.windows.forms.textbox txtport;
 private system.windows.forms.button button5;
 private system.componentmodel.container components = null;
 byte[] m_databuffer = new byte[10];
 iasyncresult result;
 public asynccallback pfncallback ;
 private system.windows.forms.label status;
 private system.windows.forms.label label5;
 public socket clientsocket;
 public form1()
 {
  initializecomponent();
 }
 private void initializecomponent()
 {
  this.label1 = new system.windows.forms.label();
  this.txtip = new system.windows.forms.textbox();
  this.label2 = new system.windows.forms.label();
  this.txtport = new system.windows.forms.textbox();
  this.label3 = new system.windows.forms.label();
  this.txtsendmsg = new system.windows.forms.richtextbox();
  this.label4 = new system.windows.forms.label();
  this.status = new system.windows.forms.label();
  this.txtrecvmsg = new system.windows.forms.richtextbox();
  this.button1 = new system.windows.forms.button();
  this.button2 = new system.windows.forms.button();
  this.button3 = new system.windows.forms.button();
  this.button4 = new system.windows.forms.button();
  this.label5 = new system.windows.forms.label();
  this.button5 = new system.windows.forms.button();
  this.suspendlayout();
  // label1
  this.label1.autosize = true;
  this.label1.location = new system.drawing.point(16, 24);
  this.label1.name = "label1";
  this.label1.size = new system.drawing.size(60, 17);
  this.label1.tabindex = 0;
  this.label1.text = "服务器ip:";
  // txtip
  this.txtip.location = new system.drawing.point(80, 24);
  this.txtip.name = "txtip";
  this.txtip.size = new system.drawing.size(160, 21);
  this.txtip.tabindex = 1;
  this.txtip.text = "";
  // label2
  this.label2.autosize = true;
  this.label2.location = new system.drawing.point(16, 56);
  this.label2.name = "label2";
  this.label2.size = new system.drawing.size(35, 17);
  this.label2.tabindex = 2;
  this.label2.text = "端口:";
  // txtport
  this.txtport.location = new system.drawing.point(80, 56);
  this.txtport.name = "txtport";
  this.txtport.size = new system.drawing.size(40, 21);
  this.txtport.tabindex = 3;
  this.txtport.text = "";
  // label3
  this.label3.autosize = true;
  this.label3.location = new system.drawing.point(16, 96);
  this.label3.name = "label3";
  this.label3.size = new system.drawing.size(110, 17);
  this.label3.tabindex = 4;
  this.label3.text = "发送信息给服务器:";
  // txtsendmsg
  this.txtsendmsg.location = new system.drawing.point(16, 120);
  this.txtsendmsg.name = "txtsendmsg";
  this.txtsendmsg.size = new system.drawing.size(224, 88);
  this.txtsendmsg.tabindex = 5;
  this.txtsendmsg.text = "";
  // label4
  this.label4.autosize = true;
  this.label4.location = new system.drawing.point(16, 248);
  this.label4.name = "label4";
  this.label4.size = new system.drawing.size(60, 17);
  this.label4.tabindex = 6;
  this.label4.text = "连接状态:";
  // status
  this.status.location = new system.drawing.point(80, 248);
  this.status.name = "status";
  this.status.size = new system.drawing.size(192, 23);
  this.status.tabindex = 7;
  // txtrecvmsg
  this.txtrecvmsg.location = new system.drawing.point(264, 80);
  this.txtrecvmsg.name = "txtrecvmsg";
  this.txtrecvmsg.readonly = true;
  this.txtrecvmsg.size = new system.drawing.size(224, 144);
  this.txtrecvmsg.tabindex = 8;
  this.txtrecvmsg.text = "";
  // button1
  this.button1.location = new system.drawing.point(280, 16);
  this.button1.name = "button1";
  this.button1.size = new system.drawing.size(88, 32);
  this.button1.tabindex = 9;
  this.button1.text = "连接";
  this.button1.click += new system.eventhandler(this.button1_click);
  // button2
  this.button2.location = new system.drawing.point(384, 16);
  this.button2.name = "button2";
  this.button2.size = new system.drawing.size(88, 32);
  this.button2.tabindex = 10;
  this.button2.text = "断开";
  this.button2.click += new system.eventhandler(this.button2_click);
  // button3
  this.button3.location = new system.drawing.point(280, 232);
  this.button3.name = "button3";
  this.button3.size = new system.drawing.size(88, 32);
  this.button3.tabindex = 11;
  this.button3.text = "清空信息";
  this.button3.click += new system.eventhandler(this.button3_click);
  // button4
  this.button4.location = new system.drawing.point(384, 232);
  this.button4.name = "button4";
  this.button4.size = new system.drawing.size(88, 32);
  this.button4.tabindex = 12;
  this.button4.text = "关闭";
  this.button4.click += new system.eventhandler(this.button4_click);
  // label5
  this.label5.autosize = true;
  this.label5.location = new system.drawing.point(264, 64);
  this.label5.name = "label5";
  this.label5.size = new system.drawing.size(134, 17);
  this.label5.tabindex = 13;
  this.label5.text = "收到服务器发来的信息:";
  // button5
  this.button5.location = new system.drawing.point(16, 208);
  this.button5.name = "button5";
  this.button5.size = new system.drawing.size(224, 32);
  this.button5.tabindex = 14;
  this.button5.text = "发送信息";
  this.button5.click += new system.eventhandler(this.button5_click);
  // form1
  this.autoscalebasesize = new system.drawing.size(6, 14);
  this.clientsize = new system.drawing.size(512, 277);
  this.controls.add(this.button5);
  this.controls.add(this.label5);
  this.controls.add(this.button4);
  this.controls.add(this.button3);
  this.controls.add(this.button2);
  this.controls.add(this.button1);
  this.controls.add(this.txtrecvmsg);
  this.controls.add(this.status);
  this.controls.add(this.label4);
  this.controls.add(this.txtsendmsg);
  this.controls.add(this.label3);
  this.controls.add(this.txtport);
  this.controls.add(this.label2);
  this.controls.add(this.txtip);
  this.controls.add(this.label1);
  this.name = "form1";
  this.text = "多人聊天程序client端";
  this.load += new system.eventhandler(this.form1_load);
  this.resumelayout(false);
 }
 #endregion
 [stathread]
 static void main()
 {
  application.run(new form1());
 }
 // 连接按钮
 private void button1_click(object sender, system.eventargs e)
 {
  // ip地址和端口号不能为空
  if(txtip.text == "" || txtport.text == "")
  {
  messagebox.show("请先完整填写服务器ip地址和端口号!", "提示");
  return;
  }
  try
  {
  // 创建socket实例
  clientsocket = new socket(addressfamily.internetwork, sockettype.stream, protocoltype.tcp);
  // 得到服务器的ip地址
  ipaddress ipaddress = ipaddress.parse(txtip.text);
  int32 port = int32.parse(txtport.text);
  // 创建远程终结点
  ipendpoint remoteep = new ipendpoint(ipaddress, port);
  // 连接到远程服务器
  clientsocket.connect(remoteep);
  if(clientsocket.connected)
  {
   updatecontrols(true);
   waitfordata(); // 异步等待数据
  }
  }
  catch(socketexception se)
  {
  messagebox.show (se.message, "提示");
  updatecontrols(false);
  }
 }
 // 等待数据
 public void waitfordata()
 {
  try
  {
  if(pfncallback == null)
  {
   // 当连接上的客户有写的操作的时候，调用回调函数
   pfncallback = new asynccallback(ondatareceived);
  }
  socketpacket socketpacket = new socketpacket();
  socketpacket.thissocket = clientsocket;
  result = clientsocket.beginreceive(socketpacket.databuffer, 0, socketpacket.databuffer.length,
   socketflags.none, pfncallback, socketpacket);
  }
  catch(socketexception se)
  {
  messagebox.show(se.message, "提示");
  }
 }
 // 该类保存socket以及发送给服务器的数据
 public class socketpacket
 {
  public system.net.sockets.socket thissocket;
  public byte[] databuffer = new byte[1024]; // 发给服务器的数据
 }
 // 接收数据
 public void ondatareceived(iasyncresult asyn)
 {
  try
  {
  socketpacket thesockid = (socketpacket)asyn.asyncstate ;
  // endreceive完成beginreceive异步调用，返回服务器写入流的字节数
  int irx = thesockid.thissocket.endreceive(asyn);
  // 加 1 是因为字符串以 '\0' 作为结束标志符
  char[] chars = new char[irx + 1];
  // 用utf8格式来将string信息转化成byte数组形式
  system.text.decoder decoder = system.text.encoding.utf8.getdecoder();
  int charlen = decoder.getchars(thesockid.databuffer, 0, irx, chars, 0);
  system.string szdata = new system.string(chars);
  // 将收到的信息显示在信息列表中
  txtrecvmsg.text = txtrecvmsg.text + szdata;
  // 等待数据
  waitfordata();
  }
  catch (objectdisposedexception)
  {
  system.diagnostics.debugger.log(0,"1","\nondatareceived: socket已经关闭!\n");
  }
  catch(socketexception se)
  {
  if(se.errorcode == 10054)
  {
   string msg = "服务器" + "停止服务!" + "\n";
   txtrecvmsg.text = txtrecvmsg.text + msg;
   clientsocket.close();
   clientsocket = null;
   updatecontrols(false);
  }
  else
  {
   messagebox.show(se.message, "提示");
  }
  }
 }
 // 更新控件。连接和断开（发送信息）按钮的状态是互斥的
 private void updatecontrols(bool connected)
 {
  button1.enabled = !connected;
  button2.enabled = connected;
  button5.enabled = connected;
  if(connected)
  {
  status.text = "已连接";
  }
  else
  {
  status.text = "无连接";
  }
 }
 // 断开按钮
 private void button2_click(object sender, system.eventargs e)
 {
  // 关闭socket
  if(clientsocket != null)
  {
  clientsocket.close();
  clientsocket = null;
  updatecontrols(false);
  }
 }
 // 发送信息按钮
 private void button5_click(object sender, system.eventargs e)
 {
  try
  {
  // 如果客户与服务器有连接，则允许发送信息
  if(clientsocket.connected)
  {
   string msg = txtsendmsg.text + "\n";
   // 用utf8格式来将string信息转化成byte数组形式
   byte[] bydata = system.text.encoding.utf8.getbytes(msg);
   if(clientsocket != null)
   {
   // 发送数据
   clientsocket.send(bydata);
   }
  }
  }
  catch(exception se)
  {
  messagebox.show(se.message, "提示");
  }
 }
 // 清空按钮
 private void button3_click(object sender, system.eventargs e)
 {
  txtrecvmsg.clear(); // 清空信息列表
 }
 // 关闭按钮
 private void button4_click(object sender, system.eventargs e)
 {
  // 关闭socket
  if(clientsocket != null)
  {
  clientsocket.close();
  clientsocket = null;
  }
  close(); // 关闭窗体
 }
 private void form1_load(object sender, system.eventargs e)
 {
  updatecontrols(false); // 初始化时，只有连接按钮可用
 }
 }
}