C#实现本地服务器客户端私聊通信
（一）需求
在游戏中我们经常能够看到玩家与玩家之间可以进行私聊，在QQ或微信中最基本的功能就是用户与用户之间的通信。抽象成计算机网络，就是两个客户端通过服务器进行私聊通信，两个客户端可以互相看到对方发送过来的信息。这种两个客户端的私聊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，我们就可以理解成两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另一个客户端。这样，一个客户端就可以接收到另一个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。两个客户端则通过打开两个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 UnityEngine;
using UnityEngine.UI;
/*
自定义网络通信共享库NetShare，包括通用数据包DataPacket、私聊频道服务器数据包PSDataPacket、
服务器数据包ServerDataPacket和私聊频道客户端数据包PCDataPacket等。
*/
using NetShare;
using System.Threading;
using System.Linq;
//私聊频道客户端
public class PersonalChannelClient : 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 Friends;//目标客户端名称下拉菜单
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, sendStr;//客户端名称和发送信息字符串
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
PCDataPacket dataPacket;//通用数据包
List desClientNames;//目标客户端名称合集
//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 = "127.0.0.1";
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();
desClientNames = new List() { "None" };
//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(() =>
{
sendStr = SendInput.text;
Thread thread = new Thread(new ThreadStart(SendDeal));
thread.Start();
SendInput.text = string.Empty;
});
}
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()) +
$"\nisLock:{isLockSend}" +
string.Format("\nPoll:{0}", currentClientSocket == null ? "None" : (!currentClientSocket.Poll(10, SelectMode.SelectRead)).ToString()) +
string.Format("\nIsConnected:{0}", currentClientSocket == null ? "False" : currentClientSocket.Connected.ToString());
//更新回显信息
if (echoContentQueue.Count > 0)
{
while (echoContentQueue.Count > 0)
{
SetEchoContents(echoContentQueue.Dequeue());
}
}
//更新聊天信息
if (chatContentQueue.Count > 0)
{
while (chatContentQueue.Count > 0)
{
SetChatContents(chatContentQueue.Dequeue());
}
}
//更新目标客户端名称下拉菜单
if (desClientNames?.Count > 0)
{
Friends.AddOptions(desClientNames);
desClientNames.Clear();
}
}
//设置回显信息相关UI的内容
void SetEchoContents(string text)
{
EchoContents.text += text;
}
//设置聊天信息相关UI的内容
void SetChatContents(string text)
{
ChatContents.text += text;
}
//执行逻辑：Socket异步连接处理
void ConnectDeal()
{
echoContentQueue.Enqueue($"\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($"\n客户端{clientName}正在断开与服务器的连接...");
if (isConnected)
{
currentClientSocket.Shutdown(SocketShutdown.Both);
currentClientSocket.BeginDisconnect(false, DisConnectCallback, currentClientSocket);
}
else echoContentQueue.Enqueue($"\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(sendStr))
{
dataPacket.mContent = sendStr;
string v_desClientName = Friends.options[Friends.value].text;
if (!v_desClientName.Equals("None")) dataPacket.mDestinationClientName = v_desClientName;
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 PCDataPacket()
{
mLocalEndPointStr = socket.LocalEndPoint.ToString(),
mClientName = clientName,
mDestinationClientName = string.Empty,
mContent = $"成功与服务器建立连接!"
};
byte[] bytes = dataPacket.ToBytes();
socket.BeginSend(bytes, 0, bytes.Length, SocketFlags.None, SendCallback, currentClientSocket);
isLockSend = false;
echoContentQueue.Enqueue($"\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);
DataPacket dataPacket = DataPacket.ToObject(buffer.Take(count).ToArray());
if (dataPacket is PSDataPacket psdp && psdp.mClientNames?.Length > 0)
{
desClientNames.Clear();
foreach (string name in psdp.mClientNames)
{
if (Friends.options.FindIndex((od) => od.text.Equals(name)) == -1) desClientNames.Add(name);
}
}
else if (dataPacket is ServerDataPacket sdp)
{
string v_res = sdp.mContent;
if (!string.IsNullOrEmpty(v_res)) chatContentQueue.Enqueue("\n" + v_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($"\n客户端{clientName}接收服务器消息失败！\n错误信息:{se.Message}");
}
}
}
服务器
using System.Net.Sockets;
using System.Net;
/*
自定义网络通信共享库NetShare，其中包括了私聊频道服务器数据包PSDataPacket、通用数据包DataPacket、
服务器数据包ServerDataPacket和私聊频道客户端数据包PCDataPacket等。
*/
using NetShare;
namespace UnityServer
{
//私聊频道服务器
internal class PersonalChannelServer
{
private static string ipAddress = "127.0.0.1";//IP地址字符串
private static int port = 5500;//端口
private static int maxConnect = 20;//最大连接数
private static byte[] buffer = new byte[1024];//消息缓冲区
//客户端Socket合集，key为IPEndPoint字符串，value为服务器为客户端分配的Socket
private static Dictionary clients = new Dictionary();
private static Socket? serverSocket;//服务器Socket
//客户端键值对，key为客户端名称，value为IPEndPoint字符串
private static Dictionary clientKVs = new Dictionary();
private static void Main(string[] args)
{
Thread thread = new Thread(new ThreadStart(ServerDeal));
thread.Start();
Console.ReadLine();
}
//判断Socket是否进行有效连接
private static bool IsConnected(Socket socket)
{
if (socket == null) return false;
return !socket.Poll(10, SelectMode.SelectRead) && socket.Connected;
}
//执行逻辑：服务器处理
private static void ServerDeal()
{
serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
IPAddress v_ipAddress = IPAddress.Parse(ipAddress);
serverSocket.Bind(new IPEndPoint(v_ipAddress, port));
serverSocket.Listen(maxConnect);
Console.WriteLine($"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(PSDataPacket dataPacket)
{
if (dataPacket == null) return;
byte[] bytes = dataPacket.ToBytes();
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();
}
}
}
//向指定的客户端发送服务器数据包
private static void SendTo(ServerDataPacket dataPacket, Socket? destinationSocket)
{
if (dataPacket == null || destinationSocket == null) return;
byte[] bytes = dataPacket.ToBytes();
if (IsConnected(destinationSocket))
{
Thread thread = new Thread(() =>
{
destinationSocket.BeginSend(bytes, 0, bytes.Length, SocketFlags.None, SendCallback, destinationSocket);
});
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);
PCDataPacket? dataPacket = DataPacket.ToObject(buffer.Take(bytesCount).ToArray());
if (dataPacket != null)
{
if (clientSocket.RemoteEndPoint != null)
{
string? v_endPointStr = clientSocket.RemoteEndPoint.ToString();
if (!string.IsNullOrEmpty(v_endPointStr))
{
clientKVs[dataPacket.mClientName] = v_endPointStr;
SendToAll(new PSDataPacket()
{
mClientNames = clientKVs.Keys.ToArray()
});
}
}
string v_content = $"客户端{dataPacket.mClientName}：{dataPacket.mContent}";
Socket? destinationSocket;
string? endPointStr;
clientKVs.TryGetValue(dataPacket.mDestinationClientName, out endPointStr);
if (!string.IsNullOrEmpty(endPointStr) && clients.TryGetValue(endPointStr, out destinationSocket))
SendTo(new ServerDataPacket() { mContent = v_content }, destinationSocket);
}
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，这里之所以启动三个客户端是为了进行对比测试，以区分多客户端的同频道通信，具体测试流程请观看下列视频：
本地服务器客户端单独通信
（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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