comwin32.cpp

一个很好用的comm类

/************************************************************************
*
*  Module name         : ComWin32.cpp
*
*  Module description  :
*     Declaration of class ComWin32.
*     ComWin32 is a class which operates the RS232 port.
*
*     NOTE:  I hate Microsoft!!!  They never give you enough information.
*
*        When using WaitCommEvent() with overlapped, the kernel will
*        remember the address of the second parameter of the function,
*        which is the address of the variable to store the value of the
*        received events.  This address will be rememberred by the kernel
*        as soon as you make the first call to the WaitCommEvent(). Bloody
*        Microsoft DOES NOT tell you that the address will be rememberred!
*        Using a local variable when calling this function will cause the
*        application to crash, sooner or later.  So DO NOT use the local
*        variable as the second parameter when calling WaitCommEvent().
*
*  Project             : Generic.
*
*  Target platform     : Win32
*
*  Compiler & Library  : Visual C++ 6.0
*
*  Author              : Richard Shen
*
*  Creation date       : 30 August, 1999
*
*  Modifications       :
*     04May03  RCS       WaitForTxComplete() added.
*
************************************************************************/
#include <windows.h>
#include "ComWin32.h"

/************************************************************************
*  Function name   : ComWin32::ComWin32
*  Description     : Constructor of class.
*                  :
*  Parameters      : portNo      - COM port.
*                  : rxBufSize   - Rx buffer size.  Default COM_RXBUFSZ.
*                  : txBufSize   - Tx buffer size.  Default COM_TXBUFSZ.
*                  : dtrInitHigh - Whether to raise DTR when openning.
*                  :               Default to TRUE.
*                  : rtsInitHigh - Whether to raise RTS when openning.
*                  :               Default to TRUE.
*  Returns         : -
*  Author          : Richard Shen
* ----------------------------------------------------------------------
*  Date     By       Description
* ----------------------------------------------------------------------
*  30Aug99  RCS      Created.
************************************************************************/
ComWin32::ComWin32(int portNo, int rxBufSize, int txBufSize,
                   BOOL dtrInitHigh, BOOL rtsInitHigh
                  )
{
   comHandle    = INVALID_HANDLE_VALUE;
   comID        = portNo;
   rxQueue      = rxBufSize;
   txQueue      = txBufSize;
   comLastError = NO_ERROR;

#ifndef NO_OVERLAPPED_SUPPORT
   comEventMask = 0;
#endif // !NO_OVERLAPPED_SUPPORT

   inHandshake  = HS_NONE;
   outHandshake = HS_NONE;
   circular     = new Circular(rxQueue);

   memset(&comDCB,      0, sizeof(DCB));
   memset(&comTimeOuts, 0, sizeof(COMMTIMEOUTS));

#ifndef NO_OVERLAPPED_SUPPORT
   memset(&ovReadWrite, 0, sizeof(OVERLAPPED));
   memset(&ovComEvent,  0, sizeof(OVERLAPPED));

   // Create an event object for COM events
   ovReadWrite.hEvent = CreateEvent(NULL, TRUE,  FALSE, NULL);
   ovComEvent.hEvent  = CreateEvent(NULL, TRUE,  FALSE, NULL);
#endif // !NO_OVERLAPPED_SUPPORT

   delayHandle        = CreateEvent(NULL, FALSE, FALSE, NULL);

   // Open and initialize the port
   Initialize(dtrInitHigh, rtsInitHigh);
} // ComWin32::ComWin32()

/************************************************************************
*  Function name   : ComWin32::~ComWin32
*  Description     : Destructor of class.
*                  :
*  Parameters      : -
*  Returns         : -
*  Author          : Richard Shen
* ----------------------------------------------------------------------
*  Date     By       Description
* ----------------------------------------------------------------------
*  30Aug99  RCS      Created.
************************************************************************/
ComWin32::~ComWin32(void)
{
   // Close COM port
   Close();

   if (circular != 0)
      delete circular;

   // Release handles
#ifndef NO_OVERLAPPED_SUPPORT
   if (ovReadWrite.hEvent != 0)
      CloseHandle(ovReadWrite.hEvent);

   if (ovComEvent.hEvent != 0)
      CloseHandle(ovComEvent.hEvent);
#endif // !NO_OVERLAPPED_SUPPORT

   if (delayHandle != 0)
      CloseHandle(delayHandle);

   return;
} // ComWin32::~ComWin32()

/************************************************************************
*  Function name   : ComWin32::IsPortAvailable
*  Description     : Check whether the object is OK to operate the port.
*                  :
*  Parameters      : -
*  Returns         : TRUE  - OK.
*                  : FALSE - Unavailable.
*  Author          : Richard Shen
* ----------------------------------------------------------------------
*  Date     By       Description
* ----------------------------------------------------------------------
*  31Aug99  RCS      Created.
************************************************************************/
BOOL ComWin32::IsPortAvailable(void)
{
   if (comHandle == INVALID_HANDLE_VALUE)
      return FALSE;

   return TRUE;
} // ComWin32::IsPortAvailable()

/************************************************************************
*  Function name   : ComWin32::Open
*  Description     : Open COM port.
*                  :
*  Parameters      : -
*  Returns         : Error code.
*  Author          : Richard Shen
* ----------------------------------------------------------------------
*  Date     By       Description
* ----------------------------------------------------------------------
*  30Aug99  RCS      Created.
************************************************************************/
DWORD ComWin32::Open(void)
{
   char  portName[MAX_PATH];

   wsprintf(portName, "\\\\.\\COM%d", comID + 1);
   comHandle = CreateFile(portName,                      // Name
                          GENERIC_READ | GENERIC_WRITE,  // Access mode
                          0,                             // Share mode
                          NULL,                          // Security attributes
                          OPEN_EXISTING,                 // How to create
#ifndef NO_OVERLAPPED_SUPPORT
                          FILE_FLAG_OVERLAPPED  |
#endif // !NO_OVERLAPPED_SUPPORT
                          FILE_ATTRIBUTE_NORMAL,         // File attributes
                          NULL                           // Template
                         );

   if (comHandle == INVALID_HANDLE_VALUE)
      comLastError = GetLastError();
   else
      comLastError = NO_ERROR;

   return comLastError;
} // ComWin32::Open()

/************************************************************************
*  Function name   : ComWin32::Close
*  Description     : Close COM port.
*                  :
*  Parameters      : -
*  Returns         : -
*  Author          : Richard Shen
* ----------------------------------------------------------------------
*  Date     By       Description
* ----------------------------------------------------------------------
*  30Aug99  RCS      Created.
************************************************************************/
void ComWin32::Close(void)
{
   if (comHandle != INVALID_HANDLE_VALUE)
   {
      SetEventMask(0);              // Disable all COM events
      LineSignal(DTR, SIGNAL_OFF);
      LineSignal(RTS, SIGNAL_OFF);
      CloseHandle(comHandle);
   } /* end of if */

   comHandle = INVALID_HANDLE_VALUE;
} // ComWin32::Close()

/************************************************************************
*  Function name   : ComWin32::Initialize
*  Description     : Open and initialize the COM port.
*                  :
*  Parameters      : dtrInitHigh -
*                  : rtsInitHigh -
*  Returns         : -
*  Author          : Richard Shen
* ----------------------------------------------------------------------
*  Date     By       Description
* ----------------------------------------------------------------------
*  30Aug99  RCS      Created.
************************************************************************/
void ComWin32::Initialize(BOOL dtrInitHigh, BOOL rtsInitHigh)
{
   if (Open() != NO_ERROR)
      return;                                // Cannot open COM port

   SetupComm(comHandle, rxQueue, txQueue);
   SetCommMask(comHandle, 0);                // Disable all events
   GetCommState(comHandle, &comDCB);         // Get the state of COM port

   // Initialize communication parameters
   comDCB.BaudRate     = CBR_19200;
   comDCB.ByteSize     = 8;
   comDCB.Parity       = NOPARITY;
   comDCB.StopBits     = ONESTOPBIT;

   comDCB.fOutxCtsFlow = 0;
   comDCB.fOutxDsrFlow = 0;
   comDCB.fDtrControl  = (dtrInitHigh) ? DTR_CONTROL_ENABLE :
                                         DTR_CONTROL_DISABLE;
   comDCB.fRtsControl  = (rtsInitHigh) ? RTS_CONTROL_ENABLE :
                                         RTS_CONTROL_DISABLE;

   comDCB.fBinary      = 1;
   comDCB.fNull        = 0;
   comDCB.EofChar      = 0;
   comDCB.EvtChar      = 0;
   comDCB.XonChar      = XON;           // Specify the Xon character
   comDCB.XoffChar     = XOFF;          // Specify the Xoff character
   comDCB.XonLim       = (unsigned short )(rxQueue / 4);
   comDCB.XoffLim      = 128;

   // Get the timeout values for the port and set our timeout values.
   COMMTIMEOUTS   newComTimeOuts;

   GetCommTimeouts(comHandle, &comTimeOuts);

   newComTimeOuts.ReadIntervalTimeout         = MAXDWORD;
   newComTimeOuts.ReadTotalTimeoutConstant    = 0;
   newComTimeOuts.ReadTotalTimeoutMultiplier  = 0;
   newComTimeOuts.WriteTotalTimeoutMultiplier = 0;
   newComTimeOuts.WriteTotalTimeoutConstant   = 0;

   SetCommTimeouts(comHandle, &newComTimeOuts);

   // Now lets try to set the port to our default values.
   if (!SetCommState(comHandle, &comDCB))
      comLastError = GetLastError();

   return;
} // ComWin32::Initialize()

/************************************************************************
*  Function name   : ComWin32::BaudRate
*  Description     : Set baud rate.
*                  :
*  Parameters      : baudRate - Baud rate to set
*  Returns         : Baud rate if successful.  0 if invalid baud rate.
*  Author          : Richard Shen
* ----------------------------------------------------------------------
*  Date     By       Description
* ----------------------------------------------------------------------
*  31Aug99  RCS      Created.
************************************************************************/
long ComWin32::BaudRate(long baudRate)
{
   DWORD    oldBaud = comDCB.BaudRate;

   comDCB.BaudRate = (DWORD )baudRate;
   if (!SetCommState(comHandle, &comDCB))
   {
      comLastError    = GetLastError();
      comDCB.BaudRate = oldBaud;

      return 0;
   } /* end of if */

   return (long )comDCB.BaudRate;
} // ComWin32::BaudRate()

/************************************************************************
*  Function name   : ComWin32::BaudRate
*  Description     : Get baud rate.
*                  :
*  Parameters      : -
*  Returns         : Baud rate.
*  Author          : Richard Shen
* ----------------------------------------------------------------------
*  Date     By       Description
* ----------------------------------------------------------------------
*  31Aug99  RCS      Created.
************************************************************************/
long ComWin32::BaudRate(void)
{
   return (long )comDCB.BaudRate;
} // ComWin32::BaudRate()

/************************************************************************
*  Function name   : ComWin32::DataLength
*  Description     : Set data length.
*                  :
*  Parameters      : length   - Data length to set to.
*  Returns         : Data length if successful.  0 if failed.
*  Author          : Richard Shen
* ----------------------------------------------------------------------
*  Date     By       Description
* ----------------------------------------------------------------------
*  31Aug99  RCS      Created.
************************************************************************/
int ComWin32::DataLength(int length)
{
   int   oldLength = comDCB.ByteSize;

   comDCB.ByteSize = length;
   if (length == 5)
      comDCB.StopBits = ONE5STOPBITS;  // 5 bits data MUST use 1.5 stop bits

   if (!SetCommState(comHandle, &comDCB))
   {
      comLastError    = GetLastError();
      comDCB.ByteSize = oldLength;

      return 0;
   } /* end of if */

   return length;
} // ComWin32::DataLength()

/************************************************************************
*  Function name   : ComWin32::DataLength
*  Description     : Get data length.
*                  :
*  Parameters      : -
*  Returns         : Data length.
*  Author          : Richard Shen
* ----------------------------------------------------------------------
*  Date     By       Description
* ----------------------------------------------------------------------
*  31Aug99  RCS      Created.
************************************************************************/
int ComWin32::DataLength(void)
{
   return (int )comDCB.ByteSize;
} // ComWin32::DataLength()

/************************************************************************
*  Function name   : ComWin32::Parity
*  Description     : Set up parity.
*                  :
*  Parameters      : parity   - Parity to set to.
*  Returns         : Parity if successful.  0 if failed.
*  Author          : Richard Shen
* ----------------------------------------------------------------------
*  Date     By       Description
* ----------------------------------------------------------------------
*  31Aug99  RCS      Created.
************************************************************************/
char ComWin32::Parity(char parity)
{
   char  oldParity = comDCB.Parity;

   switch (parity)
   {
   case 'N':
   case 'n':
      parity = NOPARITY;
      break;
   case 'E':
   case 'e':
      parity = EVENPARITY;
      break;
   case 'O':
   case 'o':
      parity = ODDPARITY;
      break;
   case 'M':
   case 'm':