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.Threading;
using System.Net;

namespace Chat_SocketServer
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            TextBox.CheckForIllegalCrossThreadCalls = false;
        }

        //服务端 监听套接字
        Socket socketWatch = null;
        //服务端 监听线程
        Thread threadWatch = null;
        //字典集合：保存通信套接字
        Dictionary<string,Socket> dictCon = new Dictionary<string,Socket>();

        private void Watch_Click(object sender, EventArgs e)
        {
            try { 
                //1.创建监听套接字 使用 ip4协议，流式传输，TCP连接 
                socketWatch = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); 
                //2.绑定端口 
                //2.1获取网络节点对象 
                IPAddress address = IPAddress.Parse(ip_txt.Text); 
                IPEndPoint endPoint = new IPEndPoint(address, int.Parse(port_txt.Text)); 
                
                //2.2绑定端口（其实内部 就向系统的 端口表中 注册 了一个端口，并指定了当前程序句柄） 
                socketWatch.Bind(endPoint); 
                //2.3设置监听队列 
                socketWatch.Listen(10); 
                //2.4开始监听,调用监听线程 执行 监听套接字的 监听方法 
                threadWatch = new Thread(WatchConnecting); 
                threadWatch.IsBackground = true; 
                threadWatch.Start(); 
                ShowMsg("服务器成功启动啦！"); 
            } catch (Exception ex) { 
                MessageBox.Show(ex.Message); 
                throw; 
            }   
        }

        private void Send_Click(object sender, EventArgs e)
        {
           
                string strClient = this.lbOnline.Text;
                if (string.IsNullOrEmpty(strClient))
                {
                    MessageBox.Show("请选择你要发送消息的客户端！");
                    return;
                }
                if (dictCon.ContainsKey(strClient))
                {
                    string strMsg = this.send_txt.Text.Trim();
                    ShowMsg("\r\n向客户端【" + strClient + "】说：" + strMsg);
                    //使用 指定的 通信套接字 将 字符串 发送到 指定的客户端 
                    byte[] arrMsg = System.Text.Encoding.UTF8.GetBytes(strMsg);
                    dictCon[strClient].Send(arrMsg);
                }
                this.send_txt.Text = "";
        }

        void WatchConnecting() { 
            //2.4开始监听：此方法会阻断当前线程，直到有 其它程序 连接过来，才执行完毕 
            Socket sokMsg = socketWatch.Accept(); 
            //将当前连接成功的 【与客户端通信的套接字】 的 标识 保存起来，并显示到 列表中 
            //将 远程客户端的 ip和端口 字符串 存入 列表 
            this.lbOnline.Items.Add(sokMsg.RemoteEndPoint.ToString()); 
            //将 服务端的通信套接字 存入 字典集合 
            dictCon.Add(sokMsg.RemoteEndPoint.ToString(), sokMsg);
            ShowMsg("\r\n客户端【" + sokMsg.RemoteEndPoint.ToString() + "】上线了！"); 
            //2.5创建 通信线程 
            Thread thrMsg = new Thread(ReceiveMsg); 
            thrMsg.IsBackground = true; 
            thrMsg.Start(sokMsg); 
        } 
        void ReceiveMsg(object obj) { 
            try { 
                Socket sokMsg = obj as Socket; 
                //3.通信套接字 监听 客户端的 消息 
                //3.1创建 消息缓存区 
                byte[] arrMsg = new byte[1024 * 1024 * 1];
                while (true) { 
                    //3.2接收客户端的消息 并存入 缓存区,注意：Receive方法也会阻断当前的线程 
                    sokMsg.Receive(arrMsg); 
                    //3.3将接收到的消息 转成 字符串 
                    string strMsg = System.Text.Encoding.UTF8.GetString(arrMsg); 
                    //3.4将消息 显示到 文本框 
                    ShowMsg("\r\n" + strMsg); 
                } 
            } catch (Exception ex) { 
                MessageBox.Show(ex.Message); throw;
            } 
        }
        void ShowMsg(string strmsg) { 
            this.show_txt.AppendText(strmsg + "\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.Sockets;
using System.Threading;
using System.Net;

namespace Chat_SocketClient
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            TextBox.CheckForIllegalCrossThreadCalls = false;
        }
        //客户端 通信套接字
        Socket socketMsg = null;
        //客户端 通信线程 
        Thread threadMsg = null;
        //标记任务
        bool isRec = true;

        private void Conn_Click(object sender, EventArgs e)
        {
            try { 
                //1.创建监听套接字 使用 ip4协议，流式传输，TCP连接 
                socketMsg = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); 
                //2.获取要连接的服务端 节点 
                //2.1获取网络节点对象 
                IPAddress address = IPAddress.Parse(ip_textbox.Text); 
                IPEndPoint endPoint = new IPEndPoint(address, 
                    int.Parse(port_textbox.Text)); 
                //3.向服务端 发送链接请求 
                socketMsg.Connect(endPoint); 
                ShowMsg("连接服务器成功~~！"); 
                //4.开启通信线程 
                threadMsg = new Thread(RecevieMsg); 
                threadMsg.IsBackground = true; 
                threadMsg.Start(); 
            } catch (Exception ex) { 
                MessageBox.Show(ex.Message); 
                throw; 
            } 
        }

        private void Send_Click(object sender, EventArgs e)
        {
            string strMsg = this.info_textbox.Text.Trim();
            byte[] arrMsg = System.Text.Encoding.UTF8.GetBytes(strMsg);
            ShowMsg("\r\n我说：" + strMsg); 
            socketMsg.Send(arrMsg); 
            this.info_textbox.Text = "";
        }

        void RecevieMsg() { 
            try { 
                //3.1创建 消息缓存区 
                byte[] arrMsg = new byte[1024 * 1024 * 1];
                while (isRec) { 
                    socketMsg.Receive(arrMsg); 
                    string strMsg = System.Text.Encoding.UTF8.GetString(arrMsg); 
                    ShowMsg("\r\n服务器说：" + strMsg); 
                 } 
            } catch (Exception ex) {
                   MessageBox.Show(ex.Message); 
                   throw; 
              } 
        } 
        void ShowMsg(string strmsg) { 
            this.richTextBox1.AppendText(strmsg + "\r\n");
        } 
       
    }
}