如何使用C#4.0编写可扩展的套接字服务器？

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

public class SocketServer
{
    private const int Port = 12345;
    private static ManualResetEvent _clientConnected = new ManualResetEvent(false);

    public static void StartListening()
    {
        IPAddress ipAddress = IPAddress.Any;
        IPEndPoint localEndPoint = new IPEndPoint(ipAddress, Port);

        Socket listener = new Socket(ipAddress.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
        listener.Bind(localEndPoint);
        listener.Listen(10);

        Console.WriteLine($"Server listening on port {Port}...");

        while (true)
        {
            _clientConnected.Reset();
            listener.BeginAccept(new AsyncCallback(AcceptCallback), listener);
            _clientConnected.WaitOne();
        }
    }

    private static void AcceptCallback(IAsyncResult ar)
    {
        _clientConnected.Set();
        Socket listener = (Socket)ar.AsyncState;
        Socket handler = listener.EndAccept(ar);

        // Process the request and send the response.
        // ...
    }
}

private static void AcceptCallback(IAsyncResult ar)
{
    _clientConnected.Set();
    Socket listener = (Socket)ar.AsyncState;
    Socket handler = listener.EndAccept(ar);

    // Process the request and send the response.
    // ...
}

private static void AcceptCallback(IAsyncResult ar)
{
    _clientConnected.Set();
    Socket listener = (Socket)ar.AsyncState;
    Socket handler = listener.EndAccept(ar);

    // Process the request and send the response.
    // ...

    // Use ThreadPool to handle the request.
    ThreadPool.QueueUserWorkItem(ProcessRequest, handler);
}

private static void ProcessRequest(object state)
{
    Socket handler = (Socket)state;
    // ...
}

private static void ProcessRequest(object state)
{
    Socket handler = (Socket)state;
    NetworkStream networkStream = new NetworkStream(handler);
    BinaryReader reader = new BinaryReader(networkStream, Encoding.UTF8, true);
    BinaryWriter writer = new BinaryWriter(networkStream, Encoding.UTF8, true);

    // Read and write data using the reader and writer.
    // ...
}

private static void ProcessRequest(object state)
{
    Socket handler = (Socket)state;
    NetworkStream networkStream = new NetworkStream(handler);
    BinaryReader reader = new BinaryReader(networkStream, Encoding.UTF8, true);
    BinaryWriter writer = new BinaryWriter(networkStream, Encoding.UTF8, true);

    // Read and write data using the reader and writer.
    // ...

    // Close the connection.
    handler.Shutdown(SocketShutdown.Both);
    handler.Close();
}