serialport.cpp

VC串口类

			}
			
		} // end switch
		
	} // close forever loop
	
	return 0;
}

//
// start comm watching
//
BOOL CSerialPort::StartMonitoring()
{
	if (!(m_Thread = AfxBeginThread(CommThread, this)))
		return FALSE;
	TRACE("Thread started\n");
	return TRUE;	
}

//
// Restart the comm thread
//
BOOL CSerialPort::RestartMonitoring()
{
	TRACE("Thread resumed\n");
	m_Thread->ResumeThread();
	return TRUE;	
}


//
// Suspend the comm thread
//
BOOL CSerialPort::StopMonitoring()
{
	TRACE("Thread suspended\n");
	m_Thread->SuspendThread(); 
	return TRUE;	
}


//
// If there is a error, give the right message
//
void CSerialPort::ProcessErrorMessage(char* ErrorText)
{
	char *Temp = new char[200];
	
	LPVOID lpMsgBuf;
	
	FormatMessage( 
		FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
		NULL,
		GetLastError(),
		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
		(LPTSTR) &lpMsgBuf,
		0,
		NULL 
		);
	
	sprintf(Temp, "WARNING:  %s Failed with the following error: \n%s\nPort: %d\n", (char*)ErrorText, lpMsgBuf, m_nPortNr); 
	MessageBox(NULL, Temp, "Application Error", MB_ICONSTOP);
	
	LocalFree(lpMsgBuf);
	delete[] Temp;
}

//
// Write a character.
//
void CSerialPort::WriteChar(CSerialPort* port)
{
	BOOL bWrite = TRUE;
	BOOL bResult = TRUE;
	
	DWORD BytesSent = 0;
	
	ResetEvent(port->m_hWriteEvent);
	
	// Gain ownership of the critical section
	EnterCriticalSection(&port->m_csCommunicationSync);
	if (bWrite)
	{
		// Initailize variables
		port->m_ov.Offset = 0;
		port->m_ov.OffsetHigh = 0;
		
		// Clear buffer
		PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);
		
		bResult = WriteFile(port->m_hComm,							// Handle to COMM Port
			port->m_szWriteBuffer,					// Pointer to message buffer in calling finction
			port->m_nWriteCount,	// Length of message to send
			&BytesSent,								// Where to store the number of bytes sent
			&port->m_ov);							// Overlapped structure
		
		// deal with any error codes
		if (!bResult)  
		{
			DWORD dwError = GetLastError();
			switch (dwError)
			{
			case ERROR_IO_PENDING:
				{
					// continue to GetOverlappedResults()
					BytesSent = 0;
					bWrite = FALSE;
					break;
				}
			default:
				{
					// all other error codes
					port->ProcessErrorMessage("WriteFile()");
				}
			}
		} 
		else
		{
			LeaveCriticalSection(&port->m_csCommunicationSync);
		}
	} // end if(bWrite)
	
	if (!bWrite)
	{
		bWrite = TRUE;
		
		bResult = GetOverlappedResult(port->m_hComm,	// Handle to COMM port 
			&port->m_ov,		// Overlapped structure
			&BytesSent,		// Stores number of bytes sent
			TRUE); 			// Wait flag
		
		LeaveCriticalSection(&port->m_csCommunicationSync);
		
		// deal with the error code 
		if (!bResult)  
		{
			port->ProcessErrorMessage("GetOverlappedResults() in WriteFile()");
		}	
	} // end if (!bWrite)
	
	// Verify that the data size send equals what we tried to send
	if (BytesSent != port->m_nWriteCount)
	{
		TRACE("WARNING: WriteFile() error.. Bytes Sent: %d; Message Length: %d\n", BytesSent,port->m_nWriteCount);
	}
}

//
// 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(unsigned char * string, int count)
{		
	assert(m_hComm != 0);
	
	memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer)); 
	memcpy(m_szWriteBuffer, string, count); 
	m_nWriteCount = count; 
	//strcpy(m_szWriteBuffer, string); 
	
	// 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;
}





UINT CSerialPort::GetPortNum()
{
return m_nPortNr;
}

void CSerialPort::Escape(DWORD dwFunc)
{
	ASSERT(IsOpen());
	
	if (!EscapeCommFunction(m_hComm, dwFunc))
	{
		TRACE(_T("Failed in call to EscapeCommFunction\n"));
		//		AfxThrowSerialException();
	}
}
void CSerialPort::ClearDTR()
{
	Escape(CLRDTR);
}

void CSerialPort::ClearRTS()
{
	Escape(CLRRTS);
}

void CSerialPort::SetDTR()
{
	Escape(SETDTR);
}

void CSerialPort::SetRTS()
{
	Escape(SETRTS);
}

void CSerialPort::SetXOFF()
{
	Escape(SETXOFF);
}

void CSerialPort::SetXON()
{
	Escape(SETXON);
}


void CSerialPort::SetBREAK()
{
Escape(SETBREAK);
}

void CSerialPort::ClearBREAK()
{
Escape(CLRBREAK);
}