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;
using System.Net.Sockets;
using System.Threading;namespace ASimpleSocketComm
{public partial class frm_Server : Form{public frm_Server(){InitializeComponent();}//窗体加载事件private void Form1_Load(object sender, EventArgs e){Control.CheckForIllegalCrossThreadCalls = false;}//开始侦听 按钮单击事件private void btn_StartLsn_Click(object sender, EventArgs e){//获取输入框中的IP地址IPAddress myip = IPAddress.Parse(txt_IP.Text);//获取输入框中的端口号int myport = int.Parse(txt_Port.Text);//构建IP终结点IPEndPoint ippoint = new IPEndPoint(myip, myport);//创建监听用的SocketSocket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);//解释：第一个参数代表使用IPV4寻址方案，第二个参数是指采用Stream方式进行通信，第三个参数是指基于TCP协议try{//将创建好的socket绑定到具体的IP终结点
                socket.Bind(ippoint);//同一时间最多接收10个客户端上线，多余的需排队socket.Listen(10);//在Server窗体中显示信息txt_SrvMsg.AppendText("服务器开始侦听...\r\n");Thread mythread = new Thread(AcceptInfo);mythread.IsBackground = true;mythread.Start(socket);}catch (Exception ex){txt_SrvMsg.AppendText(ex.Message + "\r\n");}            }//记录通信用的SocketDictionary<string, Socket> dic = new Dictionary<string, Socket>();//侦听并接收客户端上线连接void AcceptInfo(object o){Socket socket = o as Socket;//循环接收消息 死循环while (true){try{//创建通信用的socketSocket tScocket = socket.Accept();string ippoit = tScocket.RemoteEndPoint.ToString();txt_SrvMsg.AppendText(ippoit + "连接成功！\r\n");dic.Add(ippoit, tScocket);//将连接上来的客户端IPPORT保存到dic中cbx_IPEndPoint.Items.Add(ippoit);//将连接上来的客户端IPPORT添加到下拉框中//接收消息Thread th = new Thread(ReceiveMsg);th.IsBackground = true;th.Start(tScocket);}catch (Exception ex){txt_SrvMsg.AppendText(ex.Message + "\r\n");break;}}}//接收客户端发送的消息void ReceiveMsg(object o){Socket client = o as Socket;while (true){//接收客户端发送过来的数据try{//定义byte数组存放从客户端接收到的数据byte[] buffer = new byte[1024 * 1024];//将接收的数据放入buffer中，并返回实际接收数据的长度int n = client.Receive(buffer);//将字节数组转换成字符串string words = Encoding.Default.GetString(buffer, 0, n);//将接收的数据显示到Server窗体中txt_SrvMsg.AppendText(client.RemoteEndPoint.ToString() + ":" + words + "\r\n");}catch (Exception ex){txt_SrvMsg.AppendText(ex.Message + "\r\n");break;}}}//给客户端发送消息 发送消息按钮单击事件private void btn_SendMsg_Click(object sender, EventArgs e){try{//设置发送目标客户端string ipport = cbx_IPEndPoint.Text;//从下拉框中获取选中的目标IPPORTif (ipport == ""){ MessageBox.Show("请选择一个客户端！"); return; }//将要发送的数据转换为byte数组byte[] buffer = Encoding.Default.GetBytes(txt_Send.Text);//发送数据
                dic[ipport].Send(buffer);//将要发送的数据显示到Server窗体中txt_SrvMsg.AppendText(txt_Send.Text + "\r\n");}catch (Exception ex){txt_SrvMsg.AppendText(ex.Message + "\r\n");                }}}
}

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;
using System.Net.Sockets;
using System.Threading;namespace ASimpleSocketClient
{public partial class frm_Client : Form{public frm_Client(){InitializeComponent();}//窗体加载事件private void frm_Client_Load(object sender, EventArgs e){Control.CheckForIllegalCrossThreadCalls = false;}Socket client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);//连接 按钮单击事件private void btn_Connect_Click(object sender, EventArgs e){//需要连接的目标IP(服务器端的IP）IPAddress ip = IPAddress.Parse(txt_IP.Text);//目标端口（服务器端的侦听端口）int port = int.Parse(txt_Port.Text);//构建IP终结点IPEndPoint ippoint = new IPEndPoint(ip, port);try{//连接到服务器
                client.Connect(ippoint);txt_ClientMsg.AppendText("连接成功！" + "\r\n");txt_ClientMsg.AppendText("服务器:" + client.RemoteEndPoint.ToString() + "\r\n");txt_ClientMsg.AppendText("客户端:" + client.LocalEndPoint.ToString() + "\r\n");//连接成功后就可以接收服务器端发送的消息了Thread th = new Thread(ReceiveMsg);th.IsBackground = true;th.Start();}catch (Exception ex){txt_ClientMsg.AppendText(ex.Message + "\r\n");}}//接收服务器端发送的消息void ReceiveMsg(){while (true){try{byte[] buffer = new byte[1024 * 1024];int n = client.Receive(buffer);string s = Encoding.Default.GetString(buffer, 0, n);txt_ClientMsg.AppendText(client.RemoteEndPoint.ToString() + ":" + s + "\r\n");}catch (Exception ex){txt_ClientMsg.AppendText(ex.Message + "\r\n");break;}}}//发送消息 按钮单击事件private void btn_SendMsg_Click(object sender, EventArgs e){//客户端给服务器端发送消息if (client != null){try{byte[] buffer = Encoding.Default.GetBytes(txt_Send.Text);client.Send(buffer);txt_ClientMsg.AppendText(txt_Send.Text + "\r\n");}catch (Exception ex){txt_ClientMsg.AppendText(ex.Message + "\r\n");}}}        }
}