關於客戶端和服務端聊天室的思路和代碼（主要參考傳智播客講課）

服務端的代碼：

 

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.Net;
using System.Threading;
using System.IO;

namespace ItcastSocketTest
{
    /// <summary>
    /// 基本思路一、關於套接字二、關於線程
    /// 1.1、客戶端要本地的ip和一個socket相關聯--通過socketWatch.Bind(endpoint);完成
    /// 1.2、完成關聯之後就開始用用“第一線程watchTread” 監聽
    /// 1.3、監聽到客戶端之後，服務端會再創建一個負責與客戶端通信的socket----socketConnetion
    /// 2.1、客戶端與服務端的通信都通過socketConnetion來實現 包括send receive
    /// 2.2、當服務當接收信息時，要創建一個新的“第二線程recieveTread”，防止衝突
    /// 爲什麼發送不用創建線程
    /// 因爲發送消息的時間服務器不用對自己監聽 當客戶端發送消息時， 服務端要對其監聽
    /// </summary>
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            
            TextBox.CheckForIllegalCrossThreadCalls = false;
        }
        Thread watchTread=null;//創建一個線程，防止線程“死等”事件的發生
        Thread recieveTread = null;//創建一個接收線程，
        Socket socketWatch=null;//創建一個套接字用來獲取服務器的ip和端口
        Socket socketConnetion = null;//鏈接成功後返回一個套接字
        Dictionary<string,Socket> dtSocket=new Dictionary<string,Socket>();//創建一個字段，用來實現服務端向多個客戶端發送信息
        Dictionary<string, Thread> dtThread = new Dictionary<string, Thread>();//創建一個字段，用來實現服務端向多個客戶端發送信息
        /// <summary>
        /// 啓動服務端
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void BtnBeginServer_Click(object sender, EventArgs e)
        {   //創建服務器線程 負責監聽的套接字
            socketWatch = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            IPAddress address = IPAddress.Parse(txtIP.Text.ToString());
            IPEndPoint endpoint = new IPEndPoint(address, int.Parse(txtPort.Text.Trim()));
            //=========================================================
            socketWatch.Bind(endpoint);//將負責監聽的套接字綁定到指定的ip和端口上
            socketWatch.Listen(10);
            //=======================================================
            //創建監聽線程，防止UI線程與監聽線程衝突
            watchTread = new Thread(WatchConnection);
            watchTread.IsBackground = true;
            watchTread.Start();

            //========================================================
            //創建客戶端向客戶端發送消息進程
            //clientToClientThread = new Thread(recieveAndSend);
            //clientToClientThread.IsBackground = false;
            //clientToClientThread.Start();

            MsgShow("服務器監聽成功！");
        }
        /// <summary>
        /// 鏈接服務端
        /// </summary>
        void WatchConnection()
        {   
            while(true)
            {
                socketConnetion = socketWatch.Accept();//一旦監聽成功將返回一個鏈接套接字


                string strClient = socketConnetion.RemoteEndPoint.ToString();//獲取遠程客戶端的ip和port信息
                lbClientList.Items.Add(strClient);
                dtSocket.Add(strClient, socketConnetion);
                //=======================================================
                //創建接收消息進程
                recieveTread = new Thread(recievInfo);//當服務端接收消息時會和ui線程衝突，新建線程
                recieveTread.IsBackground = false;
                recieveTread.Start(socketConnetion);

                dtThread.Add(strClient,recieveTread);

                MsgShow("連接服務器成功！！" + strClient);

            }
        }

        #region 接受消息委託--recievInfo(Object socketpara)
        /// <summary>
        /// 接收消息
        /// </summary>
        void recievInfo(Object socketpara)
        {
            Socket socketRecieve = socketpara as Socket;
            while (true)
            {
                Byte[] arrMsgRec = new byte[1024 * 1024 * 2]; //用來儲存接收服務端的二進制數據
                //接收到文件的長度

                int length = socketRecieve.Receive(arrMsgRec);//完成了接受傳過來的二進制數據，並且返回一個整形數值
                if (arrMsgRec[0] == 0)
                {
                    //把接收到的消息轉化成string類型
                    string strMsgRec = System.Text.Encoding.UTF8.GetString(arrMsgRec, 1, length);
                    MsgShow(strMsgRec);
                }
                else if (arrMsgRec[0] == 1)
                {
                    SaveFileDialog sfd = new SaveFileDialog();

                    if (sfd.ShowDialog(this) == DialogResult.OK)
                    {
                        string fileSavePath = sfd.FileName;
                        using (FileStream fs = new FileStream(fileSavePath, FileMode.Create))
                        {
                            fs.Write(arrMsgRec, 1, length - 1);
                            MsgShow("文件已經保存在:" + fileSavePath);
                        }

                    }

                }

            }
        } 
        #endregion
        void MsgShow(string str)
        {
            txtMsg.AppendText(str + "\r\n");
        }

        private void btnSend_Click(object sender, EventArgs e)
        {   
            string strMsg=txtSend.Text.Trim();
            byte[] arrMsg=System.Text.Encoding.UTF8.GetBytes(strMsg);
            //====================================================================
            //找到選中客戶端，讓字典中的key值與選中客戶端的名字相同，則向他發送消息
            string strClient = lbClientList.Text;
            dtSocket[strClient].Send(arrMsg);
            MsgShow(strMsg + "已發送！");
        }

        private void btnSendToAll_Click(object sender, EventArgs e)
        {
            string strMsg = txtSend.Text.Trim();
            byte[] arrMsg = System.Text.Encoding.UTF8.GetBytes(strMsg);
            foreach (Socket s in dtSocket.Values)
            {
                s.Send(arrMsg);
            }
            MsgShow("羣發完畢~~");
        }
    }
}

客戶端代碼：

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.Net;
using System.Threading;
using System.IO;
namespace ChatClient
{
    public partial class FClient : Form
    {
        public FClient()
        {
            InitializeComponent();
            //防止出現不運行的txtMsg線程操作
            TextBox.CheckForIllegalCrossThreadCalls = false;
        }
        Socket socketClient;
        private void BtnConntionServer_Click(object sender, EventArgs e)
        {
            socketClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            IPAddress address = IPAddress.Parse(txtIP.Text.ToString());
            IPEndPoint endpoint = new IPEndPoint(address, int.Parse(txtPort.Text.Trim()));
            socketClient.Connect(endpoint);
            Thread recThread = new Thread(RecMsg);
            recThread.IsBackground = false;//防止在關閉程序後另外一個線程還在進行
            recThread.Start();//出現一個實例，一定要讓其start 說明是線程可以開始了即就緒了


        }
        void RecMsg()
        {
            while(true)
            {
                Byte[] arrMsgRec = new byte[1024 * 1024 * 2]; //用來儲存接收服務端的二進制數據
                //接收到文件的長度
                int length=socketClient.Receive(arrMsgRec);
                //把接收到的消息轉化成string類型
                string strMsgRec = System.Text.Encoding.UTF8.GetString(arrMsgRec, 0, length);
                MsgShow(strMsgRec);
            }
        }
        void MsgShow(string str)
        {
            txtMsg.AppendText(str + "\r\n");
        }

        private void btnSend_Click(object sender, EventArgs e)
        {//先與主機建立鏈接，然後讓主機產生一個負責通訊的套接字，最終由客戶端send，服務端recieve就可以
            //socketClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            //IPAddress address = IPAddress.Parse(txtIP.Text.ToString());
            //IPEndPoint endpoint = new IPEndPoint(address, int.Parse(txtPort.Text.Trim()));
            //socketClient.Connect(endpoint);
            string msg = this.txtC2S.Text.Trim();
            byte[] arrMsg = System.Text.Encoding.UTF8.GetBytes(msg);
            byte[] arrMsgSend = new byte[arrMsg.Length + 1];
            arrMsgSend[0] = 0;
            Buffer.BlockCopy(arrMsg, 0, arrMsgSend, 1, arrMsg.Length);

            socketClient.Send(arrMsgSend);
            MsgShow("已經將"+msg+"發送到服務端");
        }

        private void btnChoiceFile_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            if (ofd.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                txtFilePath.Text = ofd.FileName;
            }

        }

        private void btnSendFile_Click(object sender, EventArgs e)
        {
            using(FileStream fs=new FileStream(txtFilePath.Text,FileMode.Open))
            {
                byte[] arrFile = new byte[1024 * 1024 * 2];
                int length = fs.Read(arrFile, 0, arrFile.Length);
                byte[] arrFileSend = new byte[length + 1];
                arrFileSend[0] = 1;
                Buffer.BlockCopy(arrFile, 0,  arrFileSend,1, length );
                socketClient.Send(arrFileSend);
                MsgShow("傳送成功！");
            }
        }

    }
}