/*服務(wù)端*/

using System;
using System.Collections.Generic;
using System.Collections;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.Net.Sockets;
using System.Net;
using System.Threading;
namespace ChatSever
{       class Sever
    {
        static void Main(string[] args)
        {
            Hashtable clientTable = new Hashtable();//存放連接的轉(zhuǎn)發(fā)表            
            IPAddress ip = Dns.GetHostAddresses(Dns.GetHostName())[0];//返回主機(jī)的ip地址
            int port=9999;
            int maxsize=1024;
            TcpListener listener = new TcpListener(ip, port);
            listener.Start();
            Console.WriteLine("服務(wù)器已啟動(dòng)，正在監(jiān)聽....../n");
            Console.WriteLine(string.Format("服務(wù)器IP：{0}/t端口號(hào)：{1}/n",ip,port));
            while (true)
            {
              byte[] packetBuff=new byte[maxsize];
              Socket newClient = listener.AcceptSocket();
              newClient.Receive(packetBuff);
              string userName = Encoding.Unicode.GetString(packetBuff).TrimEnd('/0');
              if (clientTable.Count != 0 && clientTable.ContainsKey(userName))//驗(yàn)證是否為唯一用戶
              {
                  newClient.Send(Encoding.Unicode.GetBytes("Failed"));
                  continue;
              }
              else
              {
                  newClient.Send(Encoding.Unicode.GetBytes("Successful"));

              }
            //將新的連接加入轉(zhuǎn)發(fā)表并創(chuàng)建線程為其服務(wù)
              clientTable.Add(userName,newClient);
              string strlog = string.Format("[系統(tǒng)消息]用戶{0}在{1}連接.... 當(dāng)前在線人數(shù)：{2}/r/n/r/n",userName ,DateTime.Now ,clientTable.Count);
               Console.WriteLine(strlog);
               Thread thread = new Thread(new ParameterizedThreadStart(Sever.ThreadFunc));
               thread.Start(userName);
               //向所有客戶端發(fā)送系統(tǒng)消息
               foreach (DictionaryEntry de in clientTable)
               {
                   string clientName = de.Key as string;
                   Socket clientSkt = de.Value as Socket;
                   if (!clientName.Equals(userName))
                   {
                       clientSkt.Send(Encoding.Unicode.GetBytes(strlog));
                   }
               }
            }
        }

        static  void ThreadFunc(object obj)
        {
           //代碼----啟動(dòng)新的線程監(jiān)聽來自客戶端的信息     

        }
    }
}

/*客戶端：*/
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;
namespace CustomProgram
{
    class Custom
    {
        static void Main(string[] args)
        {
          byte [] data=new byte[1024];
          Socket newClient = new Socket(AddressFamily.InterNetwork ,SocketType.Stream,ProtocolType.Tcp);
          Console.WriteLine("請輸入服務(wù)器的地址：");
          string ipadd = Console.ReadLine();
          Console.WriteLine("請輸入服務(wù)的端口號(hào)：");
           int  port = Convert.ToInt32(Console.ReadLine());
          IPEndPoint ipend = new IPEndPoint(IPAddress .Parse(ipadd) ,port);
          try
          {
              newClient.Connect(ipend);//連接服務(wù)器；
          }
          catch(SocketException e)
          {
              Console.WriteLine("連接服務(wù)器失敗!");
              Console.WriteLine(e.Message);
              return;
          }
          int rec = newClient.Receive(data);
          string stringdata = Encoding.ASCII.GetString(data,0,rec);
          Console.WriteLine(stringdata);
          while (true)
          {
              string input = Console.ReadLine();
              if (input.ToUpper() == "EXIT")
                  break;
              newClient.Send(Encoding.ASCII .GetBytes(input));
              data =new byte[1024];
              rec = newClient.Receive(data);
              stringdata = Encoding.ASCII.GetString(data,0,rec);
              Console.WriteLine("{0}來自服務(wù)器消息：{1}",DateTime.Now,stringdata);
          }
          Console.WriteLine("斷開連接！");
          newClient.Shutdown(SocketShutdown.Both);
          newClient.Close();
         }
    }
}

一上完成之后，右擊項(xiàng)目解決方案的屬性把項(xiàng)目設(shè)為多啟動(dòng)，同時(shí)運(yùn)行客戶端與服務(wù)端即可；

希望這個(gè)實(shí)例能對剛學(xué)C#網(wǎng)絡(luò)編程的人有所幫助吧，小弟水平很菜，有不對的地方還請論壇里的大俠給小弟指正！