C#使用Socket实现一个socket服务器与多个socket客户端通信

　　笔记一下知识内容，原文地址：https://www.cnblogs.com/yy3b2007com/p/7476458.html

　　server端代码

　

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Net.Sockets;
using System.Net;

namespace SocketServerAcceptMultipleClient
{
    public class SocketServer
    {
        // 创建一个和客户端通信的套接字
        static Socket socketwatch = null;
        //定义一个集合，存储客户端信息
        static Dictionary<string, Socket> clientConnectionItems = new Dictionary<string, Socket> { };

        public static void Main(string[] args)
        {
            //定义一个套接字用于监听客户端发来的消息，包含三个参数（IP4寻址协议，流式连接，Tcp协议）  
            socketwatch = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            //服务端发送信息需要一个IP地址和端口号  
            IPAddress address = IPAddress.Parse("127.0.0.1");
            //将IP地址和端口号绑定到网络节点point上  
            IPEndPoint point = new IPEndPoint(address, 8098);
            //此端口专门用来监听的  

            //监听绑定的网络节点  
            socketwatch.Bind(point);

            //将套接字的监听队列长度限制为20  
            socketwatch.Listen(20);

            //负责监听客户端的线程:创建一个监听线程  
            Thread threadwatch = new Thread(watchconnecting);

            //将窗体线程设置为与后台同步，随着主线程结束而结束  
            threadwatch.IsBackground = true;

            //启动线程     
            threadwatch.Start();

            Console.WriteLine("开启监听。。。");
            Console.WriteLine("点击输入任意数据回车退出程序。。。");
            Console.ReadKey();
            Console.WriteLine("退出监听，并关闭程序。");
        }

        //监听客户端发来的请求  
        static void watchconnecting()
        {
            Socket connection = null;

            //持续不断监听客户端发来的请求     
            while (true)
            {
                try
                {
                    connection = socketwatch.Accept();
                }
                catch (Exception ex)
                {
                    //提示套接字监听异常     
                    Console.WriteLine(ex.Message);
                    break;
                }

                //获取客户端的IP和端口号  
                IPAddress clientIP = (connection.RemoteEndPoint as IPEndPoint).Address;
                int clientPort = (connection.RemoteEndPoint as IPEndPoint).Port;

                //让客户显示"连接成功的"的信息  
                string sendmsg = "连接服务端成功！\r\n" + "本地IP:" + clientIP + "，本地端口" + clientPort.ToString();
                byte[] arrSendMsg = Encoding.UTF8.GetBytes(sendmsg);
                connection.Send(arrSendMsg);

                //客户端网络结点号  
                string remoteEndPoint = connection.RemoteEndPoint.ToString();
                //显示与客户端连接情况
                Console.WriteLine("成功与" + remoteEndPoint + "客户端建立连接！\t\n");
                //添加客户端信息  
                clientConnectionItems.Add(remoteEndPoint, connection);

                //IPEndPoint netpoint = new IPEndPoint(clientIP,clientPort); 
                IPEndPoint netpoint = connection.RemoteEndPoint as IPEndPoint;

                //创建一个通信线程      
                ParameterizedThreadStart pts = new ParameterizedThreadStart(recv);
                Thread thread = new Thread(pts);
                //设置为后台线程，随着主线程退出而退出 
                thread.IsBackground = true;
                //启动线程     
                thread.Start(connection);
            }
        }

        /// 

        /// 接收客户端发来的信息，客户端套接字对象
        /// 
        ///     
        static void recv(object socketclientpara)
        {
            Socket socketServer = socketclientpara as Socket;

            while (true)
            {
                //创建一个内存缓冲区，其大小为1024*1024字节  即1M     
                byte[] arrServerRecMsg = new byte[1024 * 1024];
                //将接收到的信息存入到内存缓冲区，并返回其字节数组的长度    
                try
                {
                    int length = socketServer.Receive(arrServerRecMsg);

                    //将机器接受到的字节数组转换为人可以读懂的字符串     
                    string strSRecMsg = Encoding.UTF8.GetString(arrServerRecMsg, 0, length);

                    //将发送的字符串信息附加到文本框txtMsg上     
                    Console.WriteLine("客户端:" + socketServer.RemoteEndPoint + ",time:" + GetCurrentTime() + "\r\n" + strSRecMsg + "\r\n\n");

                    socketServer.Send(Encoding.UTF8.GetBytes("测试server 是否可以发送数据给client "));
                }
                catch (Exception ex)
                {
                    clientConnectionItems.Remove(socketServer.RemoteEndPoint.ToString());

                    Console.WriteLine("Client Count:" + clientConnectionItems.Count);

                    //提示套接字监听异常  
                    Console.WriteLine("客户端" + socketServer.RemoteEndPoint + "已经中断连接" + "\r\n" + ex.Message + "\r\n" + ex.StackTrace + "\r\n");
                    //关闭之前accept出来的和客户端进行通信的套接字 
                    socketServer.Close();
                    break;
                }
            }
        }

        ///      
        /// 获取当前系统时间的方法    
        /// 当前时间     
        static DateTime GetCurrentTime()
        {
            DateTime currentTime = new DateTime();
            currentTime = DateTime.Now;
            return currentTime;
        }
    }
}

　　client端代码

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.Threading;
using System.Net.Sockets;
using System.Net;
using System.Diagnostics;

namespace SocketClient
{
    public partial class Main : Form
    {
        //创建 1个客户端套接字 和1个负责监听服务端请求的线程  
        Thread threadclient = null;
        Socket socketclient = null;

        public Main()
        {
            InitializeComponent();

            StartPosition = FormStartPosition.CenterScreen;
            //关闭对文本框的非法线程操作检查  
            TextBox.CheckForIllegalCrossThreadCalls = false;

            this.btnSendMessage.Enabled = false;
            this.btnSendMessage.Visible = false;

            this.txtMessage.Visible = false;
        }

        private void btnConnection_Click(object sender, EventArgs e)
        {
            this.btnConnection.Enabled = false;
            //定义一个套接字监听  
            socketclient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            //获取文本框中的IP地址  
            IPAddress address = IPAddress.Parse("127.0.0.1");

            //将获取的IP地址和端口号绑定在网络节点上  
            IPEndPoint point = new IPEndPoint(address, 8098);

            try
            {
                //客户端套接字连接到网络节点上，用的是Connect  
                socketclient.Connect(point);
                this.btnSendMessage.Enabled = true;
                this.btnSendMessage.Visible = true;
                this.txtMessage.Visible = true;
            }
            catch (Exception)
            {
                Debug.WriteLine("连接失败\r\n");

                this.txtDebugInfo.AppendText("连接失败\r\n");
                return;
            }

            threadclient = new Thread(recv);
            threadclient.IsBackground = true;
            threadclient.Start();
        }

        // 接收服务端发来信息的方法    
        void recv()
        {
            int x = 0;
            //持续监听服务端发来的消息 
            while (true)
            {
                try
                {
                    //定义一个1M的内存缓冲区，用于临时性存储接收到的消息  
                    byte[] arrRecvmsg = new byte[1024 * 1024];

                    //将客户端套接字接收到的数据存入内存缓冲区，并获取长度  
                    int length = socketclient.Receive(arrRecvmsg);

                    //将套接字获取到的字符数组转换为人可以看懂的字符串  
                    string strRevMsg = Encoding.UTF8.GetString(arrRecvmsg, 0, length);
                    if (x == 1)
                    {
                        this.txtDebugInfo.AppendText("服务器:" + GetCurrentTime() + "\r\n" + strRevMsg + "\r\n\n");
                        Debug.WriteLine("服务器:" + GetCurrentTime() + "\r\n" + strRevMsg + "\r\n\n");
                    }
                    else
                    {
                        this.txtDebugInfo.AppendText(strRevMsg + "\r\n\n");
                        Debug.WriteLine(strRevMsg + "\r\n\n");
                        x = 1;
                    }
                }
                catch (Exception ex)
                {
                    Debug.WriteLine("远程服务器已经中断连接" + "\r\n\n");
                    Debug.WriteLine("远程服务器已经中断连接" + "\r\n");
                    break;
                }
            }
        }

        //获取当前系统时间  
        DateTime GetCurrentTime()
        {
            DateTime currentTime = new DateTime();
            currentTime = DateTime.Now;
            return currentTime;
        }

        //发送字符信息到服务端的方法  
        void ClientSendMsg(string sendMsg)
        {
            //将输入的内容字符串转换为机器可以识别的字节数组     
            byte[] arrClientSendMsg = Encoding.UTF8.GetBytes(sendMsg);
            //调用客户端套接字发送字节数组     
            socketclient.Send(arrClientSendMsg);
            //将发送的信息追加到聊天内容文本框中     
            Debug.WriteLine("hello...." + ": " + GetCurrentTime() + "\r\n" + sendMsg + "\r\n\n");
            this.txtDebugInfo.AppendText("hello...." + ": " + GetCurrentTime() + "\r\n" + sendMsg + "\r\n\n");
        }

        private void btnSendMessage_Click(object sender, EventArgs e)
        {
            //调用ClientSendMsg方法 将文本框中输入的信息发送给服务端     
            ClientSendMsg(this.txtMessage.Text.Trim());
            this.txtMessage.Clear();
        }
    }
}