// set buffersize for writing and save the owner m_pOwner = pPortOwner;// leak memory! if(m_szWriteBuffer) { delete m_szWriteBuffer; m_szWriteBuffer = NULL; } m_szWriteBuffer = new char[writebuffersize]; m_nPortNr = portnr; m_nWriteBufferSize = writebuffersize; m_dwCommEvents = dwCommEvents; BOOL bResult = FALSE; char *szPort = new char[50]; char *szBaud = new char[50]; // now it critical! EnterCriticalSection(&m_csCommunicationSync); // if the port is already opened: close it if (m_hComm != NULL) { CloseHandle(m_hComm); m_hComm = NULL; } // prepare port strings sprintf(szPort, "COM%d", portnr); sprintf(szBaud, "baud=%d parity=%c data=%d stop=%d", baud, parity, databits, stopbits); // get a handle to the port m_hComm = CreateFile(szPort, // communication port string (COMX) GENERIC_READ | GENERIC_WRITE, // read/write types 0, // comm devices must be opened with exclusive access NULL, // no security attributes OPEN_EXISTING, // comm devices must use OPEN_EXISTING FILE_FLAG_OVERLAPPED, // Async I/O 0); // template must be 0 for comm devices if (m_hComm == INVALID_HANDLE_VALUE) { // port not found delete [] szPort; delete [] szBaud; return FALSE; } // set the timeout values m_CommTimeouts.ReadIntervalTimeout = 1000; m_CommTimeouts.ReadTotalTimeoutMultiplier = 1000; m_CommTimeouts.ReadTotalTimeoutConstant = 1000; m_CommTimeouts.WriteTotalTimeoutMultiplier = 1000; m_CommTimeouts.WriteTotalTimeoutConstant = 1000; // configure if (SetCommTimeouts(m_hComm, &m_CommTimeouts)) { if (SetCommMask(m_hComm, dwCommEvents)) { if (GetCommState(m_hComm, &m_dcb)) { m_dcb.fRtsControl = RTS_CONTROL_ENABLE; // set RTS bit high! if (BuildCommDCB(szBaud, &m_dcb)) { if (SetCommState(m_hComm, &m_dcb)) ; // normal operation... continue else ProcessErrorMessage("SetCommState()"); } else ProcessErrorMessage("BuildCommDCB()"); } else ProcessErrorMessage("GetCommState()"); } else ProcessErrorMessage("SetCommMask()"); } else ProcessErrorMessage("SetCommTimeouts()"); delete [] szPort; delete [] szBaud; // flush the port PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT); // release critical section LeaveCriticalSection(&m_csCommunicationSync); TRACE("Initialisation for communicationport %d completed.\nUse Startmonitor to communicate.\n", portnr); return TRUE; }// The CommThread Function. // UINT CSerialPort::CommThread(LPVOID pParam) { // Cast the void pointer passed to the thread back to // a pointer of CSerialPort class CSerialPort *port = (CSerialPort*)pParam;
// Set the status variable in the dialog class to // TRUE to indicate the thread is running. port->m_bThreadAlive = 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 (;;) { // Make a call to WaitCommEvent(). This call will return immediatly // because our port was created as an async port (FILE_FLAG_OVERLAPPED // and an m_OverlappedStructerlapped structure specified). This call will cause the // m_OverlappedStructerlapped element m_OverlappedStruct.hEvent, which is part of the m_hEventArray to // be placed in a non-signeled state if there are no bytes available to be read, // or to a signeled state if there are bytes available. If this event handle // is set to the non-signeled state, it will be set to signeled when a // character arrives at the port. // we do this for each port! bResult = WaitCommEvent(port->m_hComm, &Event, &port->m_ov); if (!bResult) { // If WaitCommEvent() returns FALSE, process the last error to determin // the reason.. switch (dwError = GetLastError()) { case ERROR_IO_PENDING: { // This is a normal return value if there are no bytes // to read at the port. // Do nothing and continue break; } case 87: { // Under Windows NT, this value is returned for some reason. // I have not investigated why, but it is also a valid reply // Also do nothing and continue. break; } default:
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里面都有类似的代码,不过最好还是自己写一个,呵呵,不懂的地方MSDN一下.
// Initialize the port. This can be port 1 to 4.
//
BOOL CSerialPort::InitPort(CWnd* pPortOwner, // the owner (CWnd) of the port (receives message)
UINT portnr, // portnumber (1..4)
UINT baud, // baudrate
char parity, // parity
UINT databits, // databits
UINT stopbits, // stopbits
DWORD dwCommEvents, // EV_RXCHAR, EV_CTS etc
UINT writebuffersize) // size to the writebuffer
{
assert(portnr > 0 && portnr < 5);
assert(pPortOwner != NULL); // if the thread is alive: Kill
if (m_bThreadAlive)
{
do
{
SetEvent(m_hShutdownEvent);
} while (m_bThreadAlive);
TRACE("Thread ended\n");
} // create events
if (m_ov.hEvent != NULL)
ResetEvent(m_ov.hEvent);
m_ov.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL); if (m_hWriteEvent != NULL)
ResetEvent(m_hWriteEvent);
m_hWriteEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (m_hShutdownEvent != NULL)
ResetEvent(m_hShutdownEvent);
m_hShutdownEvent = CreateEvent(NULL, TRUE, FALSE, NULL); // initialize the event objects
m_hEventArray[0] = m_hShutdownEvent; // highest priority
m_hEventArray[1] = m_ov.hEvent;
m_hEventArray[2] = m_hWriteEvent; // initialize critical section
InitializeCriticalSection(&m_csCommunicationSync);
// set buffersize for writing and save the owner
m_pOwner = pPortOwner;// leak memory!
if(m_szWriteBuffer)
{
delete m_szWriteBuffer;
m_szWriteBuffer = NULL;
}
m_szWriteBuffer = new char[writebuffersize]; m_nPortNr = portnr; m_nWriteBufferSize = writebuffersize;
m_dwCommEvents = dwCommEvents; BOOL bResult = FALSE;
char *szPort = new char[50];
char *szBaud = new char[50]; // now it critical!
EnterCriticalSection(&m_csCommunicationSync); // if the port is already opened: close it
if (m_hComm != NULL)
{
CloseHandle(m_hComm);
m_hComm = NULL;
} // prepare port strings
sprintf(szPort, "COM%d", portnr);
sprintf(szBaud, "baud=%d parity=%c data=%d stop=%d", baud, parity, databits, stopbits); // get a handle to the port
m_hComm = CreateFile(szPort, // communication port string (COMX)
GENERIC_READ | GENERIC_WRITE, // read/write types
0, // comm devices must be opened with exclusive access
NULL, // no security attributes
OPEN_EXISTING, // comm devices must use OPEN_EXISTING
FILE_FLAG_OVERLAPPED, // Async I/O
0); // template must be 0 for comm devices if (m_hComm == INVALID_HANDLE_VALUE)
{
// port not found
delete [] szPort;
delete [] szBaud; return FALSE;
} // set the timeout values
m_CommTimeouts.ReadIntervalTimeout = 1000;
m_CommTimeouts.ReadTotalTimeoutMultiplier = 1000;
m_CommTimeouts.ReadTotalTimeoutConstant = 1000;
m_CommTimeouts.WriteTotalTimeoutMultiplier = 1000;
m_CommTimeouts.WriteTotalTimeoutConstant = 1000; // configure
if (SetCommTimeouts(m_hComm, &m_CommTimeouts))
{
if (SetCommMask(m_hComm, dwCommEvents))
{
if (GetCommState(m_hComm, &m_dcb))
{
m_dcb.fRtsControl = RTS_CONTROL_ENABLE; // set RTS bit high!
if (BuildCommDCB(szBaud, &m_dcb))
{
if (SetCommState(m_hComm, &m_dcb))
; // normal operation... continue
else
ProcessErrorMessage("SetCommState()");
}
else
ProcessErrorMessage("BuildCommDCB()");
}
else
ProcessErrorMessage("GetCommState()");
}
else
ProcessErrorMessage("SetCommMask()");
}
else
ProcessErrorMessage("SetCommTimeouts()"); delete [] szPort;
delete [] szBaud; // flush the port
PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT); // release critical section
LeaveCriticalSection(&m_csCommunicationSync); TRACE("Initialisation for communicationport %d completed.\nUse Startmonitor to communicate.\n", portnr); return TRUE;
}// The CommThread Function.
//
UINT CSerialPort::CommThread(LPVOID pParam)
{
// Cast the void pointer passed to the thread back to
// a pointer of CSerialPort class
CSerialPort *port = (CSerialPort*)pParam;
// Set the status variable in the dialog class to
// TRUE to indicate the thread is running.
port->m_bThreadAlive = TRUE;
// Misc. variables
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 (;;)
{ // Make a call to WaitCommEvent(). This call will return immediatly
// because our port was created as an async port (FILE_FLAG_OVERLAPPED
// and an m_OverlappedStructerlapped structure specified). This call will cause the
// m_OverlappedStructerlapped element m_OverlappedStruct.hEvent, which is part of the m_hEventArray to
// be placed in a non-signeled state if there are no bytes available to be read,
// or to a signeled state if there are bytes available. If this event handle
// is set to the non-signeled state, it will be set to signeled when a
// character arrives at the port. // we do this for each port! bResult = WaitCommEvent(port->m_hComm, &Event, &port->m_ov); if (!bResult)
{
// If WaitCommEvent() returns FALSE, process the last error to determin
// the reason..
switch (dwError = GetLastError())
{
case ERROR_IO_PENDING:
{
// This is a normal return value if there are no bytes
// to read at the port.
// Do nothing and continue
break;
}
case 87:
{
// Under Windows NT, this value is returned for some reason.
// I have not investigated why, but it is also a valid reply
// Also do nothing and continue.
break;
}
default: