在C#中，使用Socket實現多線程通信可以通過創建一個服務器端和客戶端并為每個連接創建單獨的線程來完成。這里是一個簡單的示例，展示了如何實現多線程Socket通信：

1. 首先，創建一個服務器端：

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;

class Server
{
    private TcpListener _listener;

    public void Start(int port)
    {
        _listener = new TcpListener(IPAddress.Any, port);
        _listener.Start();

        Console.WriteLine("Server started on port: " + port);

        while (true)
        {
            // Accept incoming connections and create a new thread for each connection
            TcpClient client = _listener.AcceptTcpClient();
            Thread clientThread = new Thread(HandleClient);
            clientThread.Start(client);
        }
    }

    private void HandleClient(object obj)
    {
        TcpClient client = (TcpClient)obj;
        NetworkStream stream = client.GetStream();

        // Read and process data from the client
        byte[] buffer = new byte[256];
        int bytesRead = stream.Read(buffer, 0, buffer.Length);
        string receivedData = System.Text.Encoding.ASCII.GetString(buffer, 0, bytesRead);

        Console.WriteLine("Received data: " + receivedData);

        // Send response to the client
        string response = "Server received: " + receivedData;
        byte[] responseData = System.Text.Encoding.ASCII.GetBytes(response);
        stream.Write(responseData, 0, responseData.Length);

        // Close the connection
        stream.Close();
        client.Close();
    }
}

2. 然后，創建一個客戶端：

using System;
using System.Net.Sockets;

class Client
{
    public void Connect(string serverIp, int port)
    {
        TcpClient client = new TcpClient(serverIp, port);
        NetworkStream stream = client.GetStream();

        // Send data to the server
        string message = "Hello, Server!";
        byte[] data = System.Text.Encoding.ASCII.GetBytes(message);
        stream.Write(data, 0, data.Length);

        // Receive response from the server
        byte[] buffer = new byte[256];
        int bytesRead = stream.Read(buffer, 0, buffer.Length);
        string response = System.Text.Encoding.ASCII.GetString(buffer, 0, bytesRead);

        Console.WriteLine("Server response: " + response);

        // Close the connection
        stream.Close();
        client.Close();
    }
}

3. 最后，在主程序中啟動服務器和客戶端：

using System;
using System.Threading;

class Program
{
    static void Main(string[] args)
    {
        // Start the server
        Server server = new Server();
        Thread serverThread = new Thread(() => server.Start(8000));
        serverThread.Start();

        // Give the server some time to start
        Thread.Sleep(1000);

        // Connect the client
        Client client = new Client();
        client.Connect("127.0.0.1", 8000);

        Console.ReadLine();
    }
}

這個示例中，服務器監聽指定端口上的連接請求，并為每個連接創建一個新線程。客戶端連接到服務器并發送一條消息，然后接收服務器的響應。這種方法可以輕松地擴展到處理多個客戶端連接。