C#实现本地服务器多客户端同频道通信
（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。
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 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();
chatContentQueue = new Queue();
//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客户端{clientName}与服务器连接成功!");
ReceiveDeal();
}
else echoContentQueue.Enqueue($"\n客户端{clientName}与服务器连接失败!");
}
catch (SocketException se)
{
echoContentQueue.Enqueue($"\n客户端{clientName}与服务器连接失败!\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($"\n客户端{clientName}与服务器断开连接操作成功!");
}
catch (SocketException se)
{
echoContentQueue.Enqueue($"\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($"\n客户端{clientName}接收服务器消息失败！\n错误信息:{se.Message}");
}
}
}
服务器
using System.Net.Sockets;
using System.Net;
using System.Text;
using NetShare;//自定义网络通信共享库，其中包括了通用数据包DataPacket、客户端数据包ClientDataPacket等
namespace UnityServer
{
//世界频道服务器
internal class WorldChannelServer
{
private static string ipAddressStr = "127.0.0.1";//IP地址字符串
private static int port = 5500;//端口
private static int maxConnectCount = 20;//最大连接数
private static byte[] buffer = new byte[1024];//消息缓冲区
//客户端Socket合集，key为IPEndPoint字符串，value为服务器为客户端分配的Socket
private static Dictionary clients = new Dictionary();
private static Socket? serverSocket;//服务器Socket
private static void Main(string[] args)
{
Thread thread = new Thread(new ThreadStart(ServerDeal));
thread.Start();
Console.ReadLine();
}
//判断Socket是否进行有效连接
private static bool IsConnected(Socket socket)
{
if (socket == null) return false;
return !socket.Poll(10, SelectMode.SelectRead) && socket.Connected;
}
//执行逻辑：服务器处理
private static void ServerDeal()
{
serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
IPAddress v_ipAddress = IPAddress.Parse(ipAddressStr);
serverSocket.Bind(new IPEndPoint(v_ipAddress, port));
serverSocket.Listen(maxConnectCount);
Console.WriteLine($"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(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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