C#实现本地服务器多客户端同频道通信

╰半橙微兮° 2024-02-18 13:32 22阅读 0赞

#### （一）需求 ####

在游戏中我们经常能够看到玩家在世界频道聊天，在QQ或微信中也有群聊功能。抽象成计算机网络，就是多个客户端通过服务器进行同频道通信，所有连接的客户端都可以看到其他客户端发送的消息。这种多客户端同频道通信是如何实现的呢？在本篇文章我们就来探讨一下。

#### （二）解决思路 ####

这个需求的重点部分在于网络通信，需要我们掌握基本的计算机网络通信知识，具体到每种编程语言又有对应的API。如果把这个需求抽象到计算机网络中，我们就可以理解成多个客户端向服务器发送信息，服务器接收信息后又把信息发送给所有连接的客户端。这样，在各个客户端就可以接收到其他客户端发送的信息了。

#### （三）设计思路 ####

服务器基于本地服务器开发，通过一个单独的C\#控制台项目模拟，编程语言使用C\#，客户端通过Unity3D构建GUI并编写客户端脚本。多客户端则通过打开多个Unity3D项目的可执行文件进行模拟，客户端的GUI需要有调试面板、客户端名称下拉菜单、连接和断开连接按钮、消息显示面板、消息输入框和消息发送按钮等。

#### （四）代码实现 ####

由于代码中引用了自定义的网络通信共享库NetShare，关于NetShare请阅读[这篇文章][Link 1]。

--------------------

***客户端***

using System;
    using System.Collections.Generic;
    using System.Net;
    using System.Net.Sockets;
    using System.Text;
    using UnityEngine;
    using UnityEngine.UI;
    using NetShare;//自定义网络通信共享库，包括通用数据包DataPacket等
    using System.Threading;
    
    //世界频道客户端
    public class WorldChannelClient : MonoBehaviour
    {
        public Text BaseInfo;//显示Socket连接基本信息的文本
        public Text EchoContents;//Socket回显信息的文本
        public Text ChatContents;//聊天信息的文本
        public Dropdown ClientMenu;//客户端名称下拉菜单
        public Button Connect;//连接按钮
        public Button DisConnect;//断开连接按钮
        public InputField SendInput;//聊天消息输入框
        public Button Send;//聊天信息发送按钮
    
        static string ipAddressStr;//IP地址字符串
        static int port;//端口
        static IPAddress iPAddress;//IP地址对象
        static IPEndPoint iPEndPoint;//IP端点对象
        string clientName;//客户端名称
        Socket currentClientSocket;//当前客户端Socket
        bool isLockSend;//是否锁定聊天信息发送按钮
        byte[] buffer;//消息接收缓冲区
        Queue<string> echoContentQueue, chatContentQueue;//回显信息队列和聊天信息队列
        DataPacket dataPacket;//通用数据包
    
        //反映Socket是否与服务器有效连接的属性
        bool isConnected
        {
            get
            {
                if (currentClientSocket == null) return false;
                return !currentClientSocket.Poll(10, SelectMode.SelectRead) && currentClientSocket.Connected;
            }
        }
    
        void Start()
        {
            //初始化
            ipAddressStr = "8.137.8.206";
            clientName = ClientMenu.options.Count > 0 ? ClientMenu.options[0].text : "";
            port = 5500;
            iPAddress = IPAddress.Parse(ipAddressStr);
            iPEndPoint = new IPEndPoint(iPAddress, port);
            buffer = new byte[1024];
            echoContentQueue = new Queue<string>();
            chatContentQueue = new Queue<string>();
    
            //为UI控件添加监听事件
            ClientMenu.onValueChanged.AddListener((index) =>
            {
                clientName = ClientMenu.options[index].text;
            });
            Connect.onClick.AddListener(() =>
            {
                Thread thread = new Thread(new ThreadStart(ConnectDeal));
                thread.Start();
            });
            DisConnect.onClick.AddListener(() =>
            {
                Thread thread = new Thread(new ThreadStart(DisConnectDeal));
                thread.Start();
            });
            Send.onClick.AddListener(() =>
            {
                Thread thread = new Thread(new ThreadStart(SendDeal));
                thread.Start();
            });
        }
    
        void Update()
        {
            //不断更新Socket基本信息
            BaseInfo.text = $"ClientName:{clientName}" +
                            string.Format("\nSocketHashCode:{0}", currentClientSocket == null ? "None" : currentClientSocket.GetHashCode().ToString()) +
                            $"\nisLock:{isLockSend}" +
                            string.Format("\nPoll:{0}", currentClientSocket == null ? "None" : (!currentClientSocket.Poll(10, SelectMode.SelectRead)).ToString()) +
                            string.Format("\nIsConnected:{0}", currentClientSocket == null ? "False" : currentClientSocket.Connected.ToString());
            //更新回显信息
            if (echoContentQueue.Count > 0)
            {
                while (echoContentQueue.Count > 0)
                {
                    SetEchoContents(echoContentQueue.Dequeue());
                }
            }
            //更新聊天信息
            if (chatContentQueue.Count > 0)
            {
                while (chatContentQueue.Count > 0)
                {
                    SetChatContents(chatContentQueue.Dequeue());
                }
            }
        }
    
        //设置回显信息相关UI的内容
        void SetEchoContents(string text)
        {
            EchoContents.text += text;
        }
    
        //设置聊天信息相关UI的内容
        void SetChatContents(string text)
        {
            ChatContents.text += text;
        }
    
        //执行逻辑：Socket异步连接处理
        void ConnectDeal()
        {
            echoContentQueue.Enqueue($"\n客户端{clientName}正在请求服务器连接...");
            Socket clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            clientSocket.BeginConnect(iPEndPoint, ConnectCallback, clientSocket);
        }
    
        //执行逻辑：Socket异步断开连接处理
        void DisConnectDeal()
        {
            echoContentQueue.Enqueue($"\n客户端{clientName}正在断开与服务器的连接...");
            if (isConnected)
            {
                currentClientSocket.Shutdown(SocketShutdown.Both);//关闭Socket的发送和接收消息功能
                currentClientSocket.BeginDisconnect(false, DisConnectCallback, currentClientSocket);
            }
            else echoContentQueue.Enqueue($"\n客户端{clientName}未与服务器建立连接,无法进行断开连接的操作...");
        }
    
        //执行逻辑：Socket异步接收信息处理
        void ReceiveDeal()
        {
            echoContentQueue.Enqueue($"\n客户端{clientName}开始监听服务器响应...");
            currentClientSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, ReceiveCallback, currentClientSocket);
        }
    
        //执行逻辑：Socket异步发送信息处理
        void SendDeal()
        {
            if (!isLockSend && !string.IsNullOrEmpty(SendInput.text))
            {
                dataPacket.mContent = SendInput.text;
                SendInput.text = string.Empty;
                byte[] bytes = dataPacket.ToBytes();
                currentClientSocket.BeginSend(bytes, 0, bytes.Length, SocketFlags.None, SendCallback, currentClientSocket);
            }
        }
    
        //执行逻辑：Socket异步连接处理回调
        void ConnectCallback(IAsyncResult ar)
        {
            try
            {
                Socket socket = ar.AsyncState as Socket;
                socket.EndConnect(ar);
                currentClientSocket = socket;
                if (isConnected)
                {
                    dataPacket = new ClientDataPacket()
                    {
                        mLocalEndPointStr = socket.LocalEndPoint.ToString(),
                        mClientName = clientName
                    };
                    isLockSend = false;
                    echoContentQueue.Enqueue($"\n<color=orange>客户端{clientName}与服务器连接成功!</color>");
                    ReceiveDeal();
                }
                else echoContentQueue.Enqueue($"\n<color=red>客户端{clientName}与服务器连接失败!</color>");
            }
            catch (SocketException se)
            {
                echoContentQueue.Enqueue($"\n<color=red>客户端{clientName}与服务器连接失败!</color>\n错误信息:{se.Message}");
            }
        }
    
        //执行逻辑：Socket异步断开连接处理回调
        void DisConnectCallback(IAsyncResult ar)
        {
            try
            {
                isLockSend = true;
                Socket socket = ar.AsyncState as Socket;
                socket.EndDisconnect(ar);
                dataPacket = null;
                echoContentQueue.Enqueue($"\n<color=orange>客户端{clientName}与服务器断开连接操作成功!</color>");
            }
            catch (SocketException se)
            {
                echoContentQueue.Enqueue($"\n客户端{clientName}与服务器断开连接操作失败！\n错误信息:{se.Message}");
            }
        }
    
        //执行逻辑：Socket异步发送信息处理回调
        void SendCallback(IAsyncResult ar)
        {
            try
            {
                Socket socket = ar.AsyncState as Socket;
                socket.EndSend(ar);
                echoContentQueue.Enqueue($"\n客户端{clientName}向服务器发送了一条消息！");
            }
            catch (SocketException se)
            {
                echoContentQueue.Enqueue($"\n客户端{clientName}向服务器发送信息操作失败！\n错误信息:{se.Message}");
            }
        }
    
        //执行逻辑：Socket异步接收信息处理回调
        void ReceiveCallback(IAsyncResult ar)
        {
            try
            {
                Socket socket = ar.AsyncState as Socket;
                int count = socket.EndReceive(ar);
                string res = Encoding.UTF8.GetString(buffer, 0, count);
                if (!string.IsNullOrEmpty(res)) chatContentQueue.Enqueue("\n" + res);
                //若Socket连接有效则继续接收消息
                if (isConnected)
                    socket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, ReceiveCallback, socket);
            }
            catch (SocketException se)
            {
                echoContentQueue.Enqueue($"\n客户端{clientName}接收服务器消息失败！\n错误信息:{se.Message}");
            }
        }
    }

--------------------

***服务器***

using System.Net.Sockets;
    using System.Net;
    using System.Text;
    using NetShare;//自定义网络通信共享库，其中包括了通用数据包DataPacket、客户端数据包ClientDataPacket等
    
    namespace UnityServer
    {
        //世界频道服务器
        internal class WorldChannelServer
        {
            private static string ipAddressStr = "127.0.0.1";//IP地址字符串
            private static int port = 5500;//端口
            private static int maxConnectCount = 20;//最大连接数
            private static byte[] buffer = new byte[1024];//消息缓冲区
    
            //客户端Socket合集，key为IPEndPoint字符串，value为服务器为客户端分配的Socket
            private static Dictionary<string, Socket> clients = new Dictionary<string, Socket>();
    
            private static Socket? serverSocket;//服务器Socket
    
            private static void Main(string[] args)
            {
                Thread thread = new Thread(new ThreadStart(ServerDeal));
                thread.Start();
                Console.ReadLine();
            }
    
            //判断Socket是否进行有效连接
            private static bool IsConnected(Socket socket)
            {
                if (socket == null) return false;
                return !socket.Poll(10, SelectMode.SelectRead) && socket.Connected;
            }
    
            //执行逻辑：服务器处理
            private static void ServerDeal()
            {
                serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                IPAddress v_ipAddress = IPAddress.Parse(ipAddressStr);
                serverSocket.Bind(new IPEndPoint(v_ipAddress, port));
                serverSocket.Listen(maxConnectCount);
                Console.WriteLine($"开启服务器[{serverSocket.LocalEndPoint}]...");
    
                serverSocket.BeginAccept(AcceptCallback, null);
            }
    
            //执行逻辑：Socket异步接收消息
            private static void ReceiveDeal(object? clientSocket)
            {
                Console.WriteLine("********************");
                if (clientSocket == null) return;
                Socket? v_clientSocket = clientSocket as Socket;
                if (v_clientSocket == null) return;
                Console.WriteLine("接收到客户端的连接请求！");
    
                if (IsConnected(v_clientSocket))
                    v_clientSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, ReceiveCallback, v_clientSocket);
            }
    
            //添加客户端Socket到客户端Socket合集
            private static void AddClient(Socket clientSocket)
            {
                if (clientSocket == null) return;
                EndPoint? endPoint = clientSocket.RemoteEndPoint;
                if (endPoint != null)
                {
                    string? v_endPointStr = endPoint.ToString();
                    if (v_endPointStr != null) clients[v_endPointStr] = clientSocket;
                }
            }
    
            //向所有客户端发送指定信息
            private static void SendToAll(string? content)
            {
                if (string.IsNullOrEmpty(content)) return;
                byte[] bytes = Encoding.UTF8.GetBytes(content);
                foreach (Socket clientSocket in clients.Values)
                {
                    if (IsConnected(clientSocket))
                    {
                        Thread thread = new Thread(() =>
                        {
                            clientSocket.BeginSend(bytes, 0, bytes.Length, SocketFlags.None, SendCallback, clientSocket);
                        });
                        thread.Start();
                    }
                }
            }
    
            //Socket监听请求回调
            private static void AcceptCallback(IAsyncResult ar)
            {
                try
                {
                    if (serverSocket != null)
                    {
                        Socket clientSocket = serverSocket.EndAccept(ar);
                        AddClient(clientSocket);
                        Thread thread = new Thread(new ParameterizedThreadStart(ReceiveDeal));
                        thread.Start(clientSocket);
                        serverSocket.BeginAccept(AcceptCallback, null);
                    }
                }
                catch (SocketException se)
                {
                    Console.WriteLine("AcceptException:" + se.Message);
                }
            }
    
            //Socket发送信息回调
            private static void SendCallback(IAsyncResult ar)
            {
                try
                {
                    Socket? clientSocket = ar.AsyncState as Socket;
                    if (clientSocket != null) clientSocket.EndSend(ar);
                }
                catch (SocketException se)
                {
                    Console.WriteLine("SendException:" + se.Message);
                }
            }
    
            //Socket接收信息回调
            private static void ReceiveCallback(IAsyncResult ar)
            {
                try
                {
                    Socket? clientSocket = ar.AsyncState as Socket;
                    if (clientSocket != null)
                    {
                        int bytesCount = clientSocket.EndReceive(ar);
                        ClientDataPacket? dataPacket = DataPacket.ToObject<ClientDataPacket>(buffer.Take(bytesCount).ToArray());
                        if (dataPacket != null)
                        {
                            string v_content = $"客户端{dataPacket.mClientName}：{dataPacket.mContent}";
                            SendToAll(v_content);
                        }
                        if (IsConnected(clientSocket))
                            clientSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, ReceiveCallback, clientSocket);
                    }
                }
                catch (SocketException se)
                {
                    Console.WriteLine("ReceiveException:" + se.Message);
                }
            }
        }
    }

#### （五）测试 ####

测试流程大概是先启动服务器，然后启动三个客户端，三个客户端分别以A、B、C的名称作为客户端名称与服务器建立连接，连接后再由客户端A、B、C分别向服务器发送信息，通过观察三个客户端的消息面板来确定测试结果，具体测试流程请观看下列视频：

本地服务器多客户端通信

#### （六）总结 ####

在服务器端，我们通过一个C\#控制台项目来模拟服务器后台，服务器与客户端具有类似的功能，同样具有发送、接收消息的功能，不同的是服务器具有监听客户端连接的功能，而客户端具有向服务器发送连接请求的功能，本质上这些都是通过Socket实现的功能，人为划分成服务器端和客户端。在客户端我们通过GUI将用户的操作进行可视化构建，实现了回显、客户端名称选择、连接、断开连接、发送和显示消息等基本交互。

为了模拟多客户端并发操作，所有功能我们都采用了异步的方式启动，对于真正的网络通信而言，这对我们来说才刚刚开始，不过通过这个案例也让我们了解了基本的网络通信流程。

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[Link 1]: http://t.csdnimg.cn/0iifP