serialport.cpp

这是一个用微软的mscomm的源码

//	if (BytesSent != strlen((char*)port->m_szWriteBuffer))
	{
//		TRACE("WARNING: WriteFile() error.. Bytes Sent: %d; Message Length: %d\n", BytesSent, strlen((char*)port->m_szWriteBuffer));
	}
//	::SendMessage((port->m_pOwner)->m_hWnd, WM_COMM_TXEMPTY_DETECTED, (WPARAM) RXBuff, (LPARAM) port->m_nPortNr);
	::SendMessage((port->m_pOwner)->m_hWnd, WM_COMM_TXEMPTY_DETECTED,0,(LPARAM) port->m_nPortNr);

}

//
// Character received. Inform the owner
//
void CSerialPort::ReceiveChar(CSerialPort* port, COMSTAT comstat)
{
	BOOL  bRead = TRUE; 
	BOOL  bResult = TRUE;
	DWORD dwError = 0;
	DWORD BytesRead = 0;
	unsigned char RXBuff;

	for (;;) 
	{ 
		// Gain ownership of the comm port critical section.
		// This process guarantees no other part of this program 
		// is using the port object. 
		
		EnterCriticalSection(&port->m_csCommunicationSync);

		// ClearCommError() will update the COMSTAT structure and
		// clear any other errors.
		
		bResult = ClearCommError(port->m_hComm, &dwError, &comstat);

		LeaveCriticalSection(&port->m_csCommunicationSync);

		// start forever loop.  I use this type of loop because I
		// do not know at runtime how many loops this will have to
		// run. My solution is to start a forever loop and to
		// break out of it when I have processed all of the
		// data available.  Be careful with this approach and
		// be sure your loop will exit.
		// My reasons for this are not as clear in this sample 
		// as it is in my production code, but I have found this 
		// solutiion to be the most efficient way to do this.
		
		if (comstat.cbInQue == 0)
		{
			// break out when all bytes have been read
			break;
		}
						
		EnterCriticalSection(&port->m_csCommunicationSync);

		if (bRead)
		{
			bResult = ReadFile(port->m_hComm,		// Handle to COMM port 
							   &RXBuff,				// RX Buffer Pointer
							   1,					// Read one byte
							   &BytesRead,			// Stores number of bytes read
							   &port->m_ov);		// pointer to the m_ov structure
			// deal with the error code 
			if (!bResult)  
			{ 
				switch (dwError = GetLastError()) 
				{ 
					case ERROR_IO_PENDING: 	
						{ 
							// asynchronous i/o is still in progress 
							// Proceed on to GetOverlappedResults();
							bRead = FALSE;
							break;
						}
					default:
						{
							// Another error has occured.  Process this error.
							port->ProcessErrorMessage("ReadFile()");
							break;
						} 
				}
			}
			else
			{
				// ReadFile() returned complete. It is not necessary to call GetOverlappedResults()
				bRead = TRUE;
			}
		}  // close if (bRead)

		if (!bRead)
		{
			bRead = TRUE;
			bResult = GetOverlappedResult(port->m_hComm,	// Handle to COMM port 
										  &port->m_ov,		// Overlapped structure
										  &BytesRead,		// Stores number of bytes read
										  TRUE); 			// Wait flag

			// deal with the error code 
			if (!bResult)  
			{
				port->ProcessErrorMessage("GetOverlappedResults() in ReadFile()");
			}	
		}  // close if (!bRead)
				
		LeaveCriticalSection(&port->m_csCommunicationSync);

		// notify parent that a byte was received
		::SendMessage((port->m_pOwner)->m_hWnd, WM_COMM_RXCHAR, (WPARAM) RXBuff, (LPARAM) port->m_nPortNr);
	} // end forever loop

}

//
// Write a string to the port
//
void CSerialPort::WriteToPort(char* string)
{		
	assert(m_hComm != 0);
	
	memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
	strcpy(m_szWriteBuffer, string);
	m_nWriteSize=strlen(string);

	// set event for write
	SetEvent(m_hWriteEvent);
}


void CSerialPort::WriteToPort(char* string,int n)
{		
	assert(m_hComm != 0);

	memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
//	memset(m_szWriteBuffer, 0, n);
//	strncpy(m_szWriteBuffer, string, n);
	memcpy(m_szWriteBuffer, string, n);
	m_nWriteSize=n;

	// set event for write
	SetEvent(m_hWriteEvent);
}

void CSerialPort::WriteToPort(LPCTSTR string)
{		
	assert(m_hComm != 0);

	memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
	strcpy(m_szWriteBuffer, string);
	m_nWriteSize=strlen(string);

	// set event for write
	SetEvent(m_hWriteEvent);
}

void CSerialPort::WriteToPort(LPCTSTR string,int n)
{		
	assert(m_hComm != 0);

	memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));
//	strncpy(m_szWriteBuffer, string, n);
	memcpy(m_szWriteBuffer, string, n);
	m_nWriteSize=n;

	// set event for write
	SetEvent(m_hWriteEvent);
}

//
// Return the device control block
//
DCB CSerialPort::GetDCB()
{
	return m_dcb;
}

//
// Return the communication event masks
//
DWORD CSerialPort::GetCommEvents()
{
	return m_dwCommEvents;
}

//
// Return the output buffer size
//
DWORD CSerialPort::GetWriteBufferSize()
{
	return m_nWriteBufferSize;
}


void CSerialPort::ClosePort()
{
	SetEvent(m_hShutdownEvent);

	/*if (m_ov.hEvent != NULL)
		CloseHandle(m_ov.hEvent);
	
	if (m_hWriteEvent != NULL)
		CloseHandle(m_hWriteEvent);
	
	if (m_hShutdownEvent != NULL)
		CloseHandle(m_hShutdownEvent);*/
	
}


BOOL CSerialPort::InitPort(CWnd *pPortOwner, UINT portnr, UINT baud, char parity, UINT databits, UINT stopbits,DWORD dwCommEvents , UINT writebuffersize)
{
	assert(portnr > 0 && portnr < 7);
	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;
	
	if (m_szWriteBuffer != NULL)
		delete [] m_szWriteBuffer;
	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
		NULL);							// template must be 0 	for comm devices
		
		if (m_hComm == INVALID_HANDLE_VALUE)
		{
			// port not found
			delete [] szPort;
			delete [] szBaud;
			
			return FALSE;
		}
		
		SetupComm(m_hComm,8092,8092);
		// 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.EvtChar = 'q';
					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;
		
}