socket通讯 多个客户端连接服务端之后如何，服务端给客户端发送信息

Question

c# socket通讯
我多个客户端与服务端建立连接后，我用某一个客户端给服务端发送信息，在服务端我该如何判断是那个客户端发送的信息呢？
或者是有什么办法在客户端对服务端建立连接时 ，给当前客户端的标识一块传给服务端呢？

Answer 1

在C#中进行Socket通信时，可以通过客户端的IP地址和端口号来标识不同的客户端。当客户端与服务端建立连接后，服务端可以获取客户端的IP地址和端口号，并将其作为标识来区分不同的客户端。
以下是一个简单的示例代码，演示了如何在服务端判断是哪个客户端发送的信息：

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
public class Server
{
    private static byte[] buffer = new byte[1024];
    private static Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
    private static int clientCount = 0;
    public static void Main(string[] args)
    {
        Console.WriteLine("Server started...");
        serverSocket.Bind(new IPEndPoint(IPAddress.Any, 8888));
        serverSocket.Listen(5);
        serverSocket.BeginAccept(new AsyncCallback(AcceptCallback), null);
        Console.ReadLine();
    }
    private static void AcceptCallback(IAsyncResult AR)
    {
        Socket socket = serverSocket.EndAccept(AR);
        clientCount++;
        Console.WriteLine("Client connected. Total clients: " + clientCount);
        socket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(ReceiveCallback), socket);
        serverSocket.BeginAccept(new AsyncCallback(AcceptCallback), null);
    }
    private static void ReceiveCallback(IAsyncResult AR)
    {
        Socket socket = (Socket)AR.AsyncState;
        int received = socket.EndReceive(AR);
        byte[] dataBuf = new byte[received];
        Array.Copy(buffer, dataBuf, received);
        string message = Encoding.ASCII.GetString(dataBuf);
        Console.WriteLine("Received from client: " + message);
        // 在这里可以根据客户端的IP地址和端口号来判断是哪个客户端发送的信息
        string clientIdentifier = socket.RemoteEndPoint.ToString();
        Console.WriteLine("Message from client " + clientIdentifier);
        socket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(ReceiveCallback), socket);
    }
}