Socket编程（三）- 实现简单的聊天程序

超、凢脫俗 2022-03-12 13:26 192阅读 0赞

### 1.服务器 ###

using System;
    using System.Net;
    using System.Net.Sockets;
    using System.Text;
    using System.Threading;
    using System.Windows.Forms;
    
    namespace Server
    {
        public partial class Form1 : Form
        {
            private Socket server;   //监听
            Socket clientSocket;     //通信
            public Form1()
            {
                InitializeComponent();
                CheckForIllegalCrossThreadCalls = false;
            }
    
            //服务器给客户端发送消息
            private void button1_Click(object sender, EventArgs e)
            {
                clientSocket.Send(Encoding.UTF8.GetBytes(writeBox.Text));
                showBox.Text += writeBox.Text + "\r\n";
                writeBox.Text = "";
            }
    
            private void Form1_Load(object sender, EventArgs e)
            {
                
                try
                {
                    server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                    IPAddress address = new IPAddress(new Byte[] { 127, 0, 0, 1 });
                    EndPoint point = new IPEndPoint(address, 7788);   //封装IP和端口号
                    server.Bind(point);
                    server.Listen(100);
                    Thread th = new Thread(socketListen);
                    th.IsBackground = true;
                    th.Start();
                }
                catch
                {
                }          
            }
            
            void socketListen()
            {           
                while (true)
                {
                    try
                    {
                        clientSocket = server.Accept();  //等待，直到接收到客户端的请求，并为之创建一个负责通信的socket
                        Thread th = new Thread(socketReceive);
                        th.IsBackground = true;
                        th.Start(clientSocket);
                    }
                    catch
                    {                
                    }               
                }
            }
    
            void socketReceive(object obj)
            {
                Socket clientSocket = obj as Socket;
                while (true)
                {
                    try
                    {
                        byte[] data = new byte[1024 * 1024];
                        int length = clientSocket.Receive(data);
                        if (length == 0)
                            break;
                        string message = Encoding.UTF8.GetString(data, 0, length);
                        showBox.Text += clientSocket.RemoteEndPoint.ToString() + ":" + message + "\r\n";
                        writeBox.Text = "";
                    }
                    catch
                    {               
                    }             
                }
            }
        }
    }

### 2.客户端 ###

using System;
    using System.Net;
    using System.Net.Sockets;
    using System.Text;
    using System.Threading;
    using System.Windows.Forms;
    
    namespace Client
    {
        public partial class Form1 : Form
        {
            Socket client = null;
            public Form1()
            {
                InitializeComponent();
                CheckForIllegalCrossThreadCalls = false;
            }
    
            private void button1_Click(object sender, EventArgs e)
            {
                client.Send(Encoding.UTF8.GetBytes(writeBox.Text));
                showBox.Text += writeBox.Text + "\r\n";
                writeBox.Text = "";
            }
    
            private void Form1_Load(object sender, EventArgs e)
            {
                try
                {
                    //创建客户端socket
                    client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                    //发起建立连接的请求
                    IPAddress address = IPAddress.Parse("127.0.0.1");
                    EndPoint point = new IPEndPoint(address, 7788);
                    client.Connect(point);
                    //接收服务器的消息
                    Thread th = new Thread(socketReceive);
                    th.IsBackground = true;
                    th.Start();
                }
                catch
                {              
                }           
            }
    
            void socketReceive()
            {
                while (true)
                {
                    try
                    {
                        byte[] data = new byte[1024 * 1024];
                        int length = client.Receive(data);   //length表示接收到的数据的长度
                        if (length == 0)
                            break;
                        string message = Encoding.UTF8.GetString(data, 0, length);
                        showBox.Text += client.RemoteEndPoint.ToString() + ":" + message + "\r\n";
                    }
                    catch 
                    {                  
                    }
                }
            }
        }
    }

### 3.运行结果 ###

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpeWF6aGVuMjAxMQ_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpeWF6aGVuMjAxMQ_size_16_color_FFFFFF_t_70 1][]

### 4.分析 ###

该程序中，服务器可以一直监听客户端的连接，可以接收多条客户端发来的信息。但是有一个缺点，后来的客户端连接会覆盖掉先前的连接，即：服务器无法给较早连接进来的客户端发送信息。在后面的文章中，会解决这一问题。

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