Question

我正在为一个控制LED灯的网络连接微控制器编写一个测试程序。

当我尝试从远程主机接收答案时，整个过程卡在socket.receive函数中。

我使用套接字向远程主机发送几个字节的数据。然后我听取了数据。但是在我收到数据的时候，程序就会在没有例外的情况下停止。

发送功能：

    public void Send(Command cmd)
    {
        switch (cmd.command)
        {
            case CommandType.SetAll:
                send_data(SET_COLOR_ALL, cmd.data, 3);
                break;
            case CommandType.SetRed:
                send_data(SET_COLOR_RED, cmd.data, 1);
                break;
            case CommandType.SetGreen:
                send_data(SET_COLOR_GREEN, cmd.data, 1);
                break;
            case CommandType.SetBlue:
                send_data(SET_COLOR_BLUE, cmd.data, 1);
                break;
            case CommandType.GetColor:
                Debug.WriteLine("Sending request...");
                send_data(GET_COLOR, cmd.data, 0);
                read_data(); //here it gets stuck !
                break;
        }
        m_socket.Disconnect(true);
    }

从read_data（）中提取

    private void read_data()
    {
        Debug.WriteLine("Called read_data()");
        byte[] t_buffer = new byte[4];
        try
        {
            if(!m_socket.Connected)
                m_socket.Listen(10000);
            sock_receive(m_socket, ref t_buffer, 0, t_buffer.Length, 10000);
        }
        catch (Exception ex) { 
            throw ex; 
        }
        finally { // do some stuff here }
   }

这里是sock_receive函数，其中一切都被卡住了：

    public static void sock_receive(Socket socket,ref byte[] buffer, int offset, int size, int timeout)
    {
        int startTickCount = Environment.TickCount;
        int received = 0;  // how many bytes is already received
        do
        {
            Debug.WriteLine("In Loop..");
            if (Environment.TickCount > startTickCount + timeout)
                throw new Exception("Timeout.");
            try
            {
                //here it gets stuck !
                received += socket.Receive(buffer, offset + received, size - received, SocketFlags.None); 
                Debug.WriteLine("Byte arrived, received : " + received.ToString());
            }
            catch (SocketException ex)
            {
                Debug.WriteLine("Socket exception !");
                if (ex.SocketErrorCode == SocketError.WouldBlock ||
                    ex.SocketErrorCode == SocketError.IOPending ||
                    ex.SocketErrorCode == SocketError.NoBufferSpaceAvailable)
                {
                    // socket buffer is probably empty, wait and try again
                    Thread.Sleep(30);
                }
                else
                    throw ex;  // any serious error occurr
            }
        } while (received < size);
    }

我希望你们能帮帮我。

问候

n0pt3x

Answer 1

我是对的，m_socket是一个侦听连接的服务器套接字吗？当然，您无法从中接收数据，您必须先调用Accept（），然后从它返回的套接字中读取。

接收数据的C＃套接字问题

1 个答案: