接收消息并通过NetworkStream将消息发送到客户端

Question

我有一个问题，有关通过C＃通过网络流从TCPListener服务器向客户端发送和接收消息。现在，我的TCPListener实例可以从客户端接收一条消息并将其写入服务器控制台，并且可以接受一个输入字符串并将其发送回客户端。但我希望改进该功能，以接受来自客户端的多个连续消息并将多个连续响应发送回客户端。如果NetworkStream的ReadAsync和WriteAsync函数可以处理接收多个连续的消息或发送多个连续的消息，并且有更好的方法可以实现，那么是否有人碰巧拥有任何指针？另外，由于Console.ReadLine函数将在服务器从未从ReadLine接收到任何用户输入（并且没有按Enter键）的情况下阻塞，是否有办法测试键盘是否有可选的用户输入？这样，仅当服务器从用户那里收到某种控制台输入时，我才能尝试执行send message命令，否则可以继续接收客户端消息。

   public static async Task getMessage(TcpListener server)
      {
            byte[] bytes = new byte[256];
            using (var theStream = await server.AcceptTcpClientAsync())
            {
                using (var tcpStream = theStream.GetStream())
                {

                    await tcpStream.ReadAsync(bytes, 0, bytes.Length);
                    var msg = Encoding.UTF8.GetString(bytes);
                    Console.WriteLine(msg);
                    var payload = Console.ReadLine();
                    var bytes2 = Encoding.UTF8.GetBytes(payload);
                    await tcpStream.WriteAsync(bytes2, 0, bytes2.Length);
                }

           }

      } 

Answer 1

很有趣的是，看到一个仅用于一个客户端的服务器实现！

TCP是一种双向通信协议，因此，可以，您当然可以发送所需的内容，并在需要时同时接收任何内容。

我试图在源代码中添加评论以使其自我解释。

但是关键是将TcpClient和NetworkStream实例声明为静态变量，以便主线程（从控制台读取并将有效载荷发送到客户端的线程可以访问它们）

希望这会有所帮助。

public static async Task getMessage(TcpListener server)
{
    byte[] bytes = new byte[256];
    using (theStream = await server.AcceptTcpClientAsync())
    {
        using (tcpStream = theStream.GetStream())
        {
            // We are using an infinite loop which ends when zero bytes have been received.
            // Receiving zero bytes means the transmission is over (client disconnected)
            while (await tcpStream.ReadAsync(bytes, 0, bytes.Length) > 0)
            {
                var msg = Encoding.UTF8.GetString(bytes);
                Console.WriteLine(msg);
            }
            Console.WriteLine("Client has disconnected");
        }
    }
}

/// <summary>
/// Transmists the payload to the client
/// </summary>
/// <param name="payload">The payload to transmit to the client</param>
/// <returns></returns>
static async Task Transmit(string payload)
{
    var bytes2 = Encoding.UTF8.GetBytes(payload);
    await tcpStream.WriteAsync(bytes2, 0, bytes2.Length);
}

// We are declaring the TcpClient and NetworkStream as static variables
// to be able to access them from all the threads.
private static TcpClient theStream;
public static NetworkStream tcpStream;

static void Main(string[] args)
{
    TcpListener server = new TcpListener(IPAddress.Loopback, 9876);
    server.Start();

    // Start the task getMessage() to accept a client and receive
    Task.Run(() => getMessage(server));

    string payload;
    while ((payload = Console.ReadLine()) != "exit")
    {
        // Check if the client has connected.
        if (tcpStream != null)
        {
            // Check if they are still connected
            if (theStream.Client.Connected)
            {
                Task.Run(() => Transmit(payload));
            }
            else
            {
                Console.WriteLine("the client connection is lost");
                break;
            }
        }
        else
        {
            Console.WriteLine("The client has not connected yet.");
        }
    }

    Console.WriteLine("Stopping the server");
    server.Stop();
}