SerialPort串口类工程

/* Module : SERIALPORT.CPP Purpose: Implementation for an MFC wrapper class for serial ports Created: PJN / 31-05-1999 History: PJN / 03-06-1999 1. Fixed problem with code using CancelIo which does not exist on 95. 2. Fixed leaks which can occur in sample app when an exception is thrown PJN / 16-06-1999 1. Fixed a bug whereby CString::ReleaseBuffer was not being called in CSerialException::GetErrorMessage PJN / 29-09-1999 1. Fixed a simple copy and paste bug in CSerialPort::SetDTR Copyright (c) 1999 by PJ Naughter. All rights reserved. */ ///////////////////////////////// Includes ////////////////////////////////// #include "stdafx.h" #include "serialport.h" #include "winerror.h" ///////////////////////////////// defines ///////////////////////////////////// #ifdef _DEBUG #define new DEBUG_NEW #undef THIS_FILE static char THIS_FILE[] = __FILE__; #endif //////////////////////////////// Implementation /////////////////////////////// //Class which handles CancelIo function which must be constructed at run time //since it is not imeplemented on NT 3.51 or Windows 95. To avoid the loader //bringing up a message such as "Failed to load due to missing export...", the //function is constructed using GetProcAddress. The CSerialPort::CancelIo //function then checks to see if the function pointer is NULL and if it is it //throws an exception using the error code ERROR_CALL_NOT_IMPLEMENTED which //is what 95 would have done if it had implemented a stub for it in the first //place !! class _SERIAL_PORT_DATA { public: //Constructors /Destructors _SERIAL_PORT_DATA(); ~_SERIAL_PORT_DATA(); HINSTANCE m_hKernel32; typedef BOOL (CANCELIO)(HANDLE); typedef CANCELIO* LPCANCELIO; LPCANCELIO m_lpfnCancelIo; }; _SERIAL_PORT_DATA::_SERIAL_PORT_DATA() { m_hKernel32 = LoadLibrary(_T("KERNEL32.DLL")); VERIFY(m_hKernel32 != NULL); m_lpfnCancelIo = (LPCANCELIO) GetProcAddress(m_hKernel32, "CancelIo"); } _SERIAL_PORT_DATA::~_SERIAL_PORT_DATA() { FreeLibrary(m_hKernel32); m_hKernel32 = NULL; } //The local variable which handle the function pointers _SERIAL_PORT_DATA _SerialPortData; ////////// Exception handling code void AfxThrowSerialException(DWORD dwError /* = 0 */) { if (dwError == 0) dwError = ::GetLastError(); CSerialException* pException = new CSerialException(dwError); TRACE(_T("Warning: throwing CSerialException for error %d\n"), dwError); THROW(pException); } BOOL CSerialException::GetErrorMessage(LPTSTR pstrError, UINT nMaxError, PUINT pnHelpContext) { ASSERT(pstrError != NULL && AfxIsValidString(pstrError, nMaxError)); if (pnHelpContext != NULL) *pnHelpContext = 0; LPTSTR lpBuffer; BOOL bRet = FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, NULL, m_dwError, MAKELANGID(LANG_NEUTRAL, SUBLANG_SYS_DEFAULT), (LPTSTR) &lpBuffer, 0, NULL); if (bRet == FALSE) *pstrError = '\0'; else { lstrcpyn(pstrError, lpBuffer, nMaxError); bRet = TRUE; LocalFree(lpBuffer); } return bRet; } CString CSerialException::GetErrorMessage() { CString rVal; LPTSTR pstrError = rVal.GetBuffer(4096); GetErrorMessage(pstrError, 4096, NULL); rVal.ReleaseBuffer(); return rVal; } CSerialException::CSerialException(DWORD dwError) { m_dwError = dwError; } CSerialException::~CSerialException() { } IMPLEMENT_DYNAMIC(CSerialException, CException) #ifdef _DEBUG void CSerialException::Dump(CDumpContext& dc) const { CObject::Dump(dc); dc << "m_dwError = " << m_dwError; } #endif ////////// The actual serial port code CSerialPort::CSerialPort() { m_hComm = INVALID_HANDLE_VALUE; m_bOverlapped = FALSE; } CSerialPort::~CSerialPort() { Close(); } IMPLEMENT_DYNAMIC(CSerialPort, CObject) #ifdef _DEBUG void CSerialPort::Dump(CDumpContext& dc) const { CObject::Dump(dc); dc << _T("m_hComm = ") << m_hComm << _T("\n"); dc << _T("m_bOverlapped = ") << m_bOverlapped; } #endif void CSerialPort::Open(int nPort, DWORD dwBaud, Parity parity, BYTE DataBits, StopBits stopbits, FlowControl fc, BOOL bOverlapped) { //Validate our parameters ASSERT(nPort>0 && nPort<=255); //Call CreateFile to open up the comms port CString sPort; sPort.Format(_T("\\\\.\\COM%d"), nPort); m_hComm = CreateFile(sPort, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, bOverlapped ? FILE_FLAG_OVERLAPPED : 0, NULL); if (m_hComm == INVALID_HANDLE_VALUE) { TRACE(_T("Failed to open up the comms port\n")); AfxThrowSerialException(); } m_bOverlapped = bOverlapped; //Get the current state prior to changing it DCB dcb; GetState(dcb); //Setup the baud rate dcb.BaudRate = dwBaud; //Setup the Parity switch (parity) { case EvenParity: dcb.Parity = EVENPARITY; break; case MarkParity: dcb.Parity = MARKPARITY; break; case NoParity: dcb.Parity = NOPARITY; break; case OddParity: dcb.Parity = ODDPARITY; break; case SpaceParity: dcb.Parity = SPACEPARITY; break; default: ASSERT(FALSE); break; } //Setup the data bits dcb.ByteSize = DataBits; //Setup the stop bits switch (stopbits) { case OneStopBit: dcb.StopBits = ONESTOPBIT; break; case OnePointFiveStopBits: dcb.StopBits = ONE5STOPBITS; break; case TwoStopBits: dcb.StopBits = TWOSTOPBITS; break; default: ASSERT(FALSE); break; } //Setup the flow control dcb.fDsrSensitivity = FALSE; switch (fc) { case NoFlowControl: { dcb.fOutxCtsFlow = FALSE; dcb.fOutxDsrFlow = FALSE; dcb.fOutX = FALSE; dcb.fInX = FALSE; break; } case CtsRtsFlowControl: { dcb.fOutxCtsFlow = TRUE; dcb.fOutxDsrFlow = FALSE; dcb.fRtsControl = RTS_CONTROL_HANDSHAKE; dcb.fOutX = FALSE; dcb.fInX = FALSE; break; } case CtsDtrFlowControl: { dcb.fOutxCtsFlow = TRUE; dcb.fOutxDsrFlow = FALSE; dcb.fDtrControl = DTR_CONTROL_HANDSHAKE; dcb.fOutX = FALSE; dcb.fInX = FALSE; break; } case DsrRtsFlowControl: { dcb.fOutxCtsFlow = FALSE; dcb.fOutxDsrFlow = TRUE; dcb.fRtsControl = RTS_CONTROL_HANDSHAKE; dcb.fOutX = FALSE; dcb.fInX = FALSE; break; } case DsrDtrFlowControl: { dcb.fOutxCtsFlow = FALSE; dcb.fOutxDsrFlow = TRUE; dcb.fDtrControl = DTR_CONTROL_HANDSHAKE; dcb.fOutX = FALSE; dcb.fInX = FALSE; break; } case XonXoffFlowControl: { dcb.fOutxCtsFlow = FALSE; dcb.fOutxDsrFlow = FALSE; dcb.fOutX = TRUE; dcb.fInX = TRUE; dcb.XonChar = 0x11; dcb.XoffChar = 0x13; dcb.XoffLim = 100; dcb.XonLim = 100; break; } default: { ASSERT(FALSE); break; } } //Now that we have all the settings in place, make the changes SetState(dcb); } void CSerialPort::Close() { if (IsOpen()) { BOOL bSuccess = CloseHandle(m_hComm); m_hComm = INVALID_HANDLE_VALUE; if (!bSuccess) TRACE(_T("Failed to close up the comms port, GetLastError:%d\n"), GetLastError()); m_bOverlapped = FALSE; } } void CSerialPort::Attach(HANDLE hComm) { Close(); m_hComm = hComm; } HANDLE CSerialPort::Detach() { HANDLE hrVal = m_hComm; m_hComm = INVALID_HANDLE_VALUE; return hrVal; } DWORD CSerialPort::Read(void* lpBuf, DWORD dwCount) { ASSERT(IsOpen()); ASSERT(!m_bOverlapped); DWORD dwBytesRead = 0; if (!ReadFile(m_hComm, lpBuf, dwCount, &dwBytesRead, NULL)) {