郁闷，请问，我用串口通讯写的一程序，在用F9设置断点的情况，可以正常运行，可是把断点取点后，就像没有收到数据一样没有反应，是那里的

Question

如题,谢谢!!!

Answer 1

DWORD _stdcall TGGCommunication::CommThread(LPVOID pParam)
{
    TGGCommunication *port = (TGGCommunication*)pParam;
    port->m_bThreadAlive = true;
    //DWORD BytesTransfered = 0;
    DWORD Event = 0;
    DWORD CommEvent = 0;
    DWORD dwError = 0;
    COMSTAT comstat;
    BOOL  bResult = true;    // Clear comm buffers at startup
    if (port->m_hComm)  // check if the port is opened
        PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);    // begin forever loop.  This loop will run as long as the thread is alive.
        for (;;)
        {
            bResult = WaitCommEvent(port->m_hComm, &Event, &port->m_ov);
            if (!bResult)
            {
                switch (dwError = GetLastError())
                {
                    case ERROR_IO_PENDING:
                    {
                        break;
                    }
                    case 87:
                    {
                        break;
                    }
                    default:
                    {
                        port->ProcessErrorMessage("WaitCommEvent()");
                        break;
                    }
                }
            }
            else
            {
                bResult = ClearCommError(port->m_hComm, &dwError, &comstat);
                if (comstat.cbInQue == 0)
                    continue;
            } // end if bResult
            Event = WaitForMultipleObjects(3, port->m_hEventArray, false, INFINITE);
            switch (Event)
            {
                case 0:
                {
                    port->m_bThreadAlive = false;
                    ExitThread(100);
                    break;
                }
                case 1: // read event
                {
                    GetCommMask(port->m_hComm, &CommEvent);
                    if (CommEvent & EV_CTS)
                        ::SendMessage(port->m_pOwner->Handle, WM_COMM_CTS_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
                    if (CommEvent & EV_RXFLAG)
                        ::SendMessage(port->m_pOwner->Handle, WM_COMM_RXFLAG_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
                    if (CommEvent & EV_BREAK)
                        ::SendMessage(port->m_pOwner->Handle, WM_COMM_BREAK_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
                    if (CommEvent & EV_ERR)
                        ::SendMessage(port->m_pOwner->Handle, WM_COMM_ERR_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
                    if (CommEvent & EV_RING)
                        ::SendMessage(port->m_pOwner->Handle, WM_COMM_RING_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);
                    if (CommEvent & EV_RXCHAR)
                        ReceiveChar(port, comstat);
                    break;
                }
                case 2:
                {
                    WriteChar(port);
                    break;
                }
            }// end switch
        }// close forever loop
    }
    delete port;
}

Answer 2

可以在收之前sleep一下。
因为你去收的时候设备未必准备好你去读数据了。

Answer 3

Sleep(）
因为你断点调试时相当于作了Sleep()操作。