Windows编程

开发平台：
Visual C++

Serial.cpp：源码内容
							// Serial.cpp
#include "stdafx.h"
#include "Serial.h"
CSerial::CSerial()
{
	memset( &m_OverlappedRead, 0, sizeof( OVERLAPPED ) );
 	memset( &m_OverlappedWrite, 0, sizeof( OVERLAPPED ) );
	m_hIDComDev = NULL;
	m_bOpened = FALSE;
}
CSerial::~CSerial()
{
	Close();
}
BOOL CSerial::Open( int nPort, int nBaud )
{
	if( m_bOpened ) return( TRUE );
	char szPort[15];
	char szComParams[50];
	DCB dcb;
	wsprintf( szPort, "COM%d", nPort );
	m_hIDComDev = CreateFile( szPort, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, NULL );
	if( m_hIDComDev == NULL ) return( FALSE );
	memset( &m_OverlappedRead, 0, sizeof( OVERLAPPED ) );
 	memset( &m_OverlappedWrite, 0, sizeof( OVERLAPPED ) );
	COMMTIMEOUTS CommTimeOuts;
	CommTimeOuts.ReadIntervalTimeout = 0xFFFFFFFF;
	CommTimeOuts.ReadTotalTimeoutMultiplier = 0;
	CommTimeOuts.ReadTotalTimeoutConstant = 0;
	CommTimeOuts.WriteTotalTimeoutMultiplier = 0;
	CommTimeOuts.WriteTotalTimeoutConstant = 5000;
	SetCommTimeouts( m_hIDComDev, &CommTimeOuts );
	wsprintf( szComParams, "COM%d:%d,n,8,1", nPort, nBaud );
	m_OverlappedRead.hEvent = CreateEvent( NULL, TRUE, FALSE, NULL );
	m_OverlappedWrite.hEvent = CreateEvent( NULL, TRUE, FALSE, NULL );
	dcb.DCBlength = sizeof( DCB );
	GetCommState( m_hIDComDev, &dcb );
	dcb.BaudRate = nBaud;
	dcb.ByteSize = 8;
	unsigned char ucSet;
	ucSet = (unsigned char) ( ( FC_RTSCTS & FC_DTRDSR ) != 0 );
	ucSet = (unsigned char) ( ( FC_RTSCTS & FC_RTSCTS ) != 0 );
	ucSet = (unsigned char) ( ( FC_RTSCTS & FC_XONXOFF ) != 0 );
	if( !SetCommState( m_hIDComDev, &dcb ) ||
		!SetupComm( m_hIDComDev, 10000, 10000 ) ||
		m_OverlappedRead.hEvent == NULL ||
		m_OverlappedWrite.hEvent == NULL ){
		DWORD dwError = GetLastError();
		if( m_OverlappedRead.hEvent != NULL ) CloseHandle( m_OverlappedRead.hEvent );
		if( m_OverlappedWrite.hEvent != NULL ) CloseHandle( m_OverlappedWrite.hEvent );
		CloseHandle( m_hIDComDev );
		return( FALSE );
		}
	m_bOpened = TRUE;
	return( m_bOpened );
}
BOOL CSerial::Close( void )
{
	if( !m_bOpened || m_hIDComDev == NULL ) return( TRUE );
	if( m_OverlappedRead.hEvent != NULL ) CloseHandle( m_OverlappedRead.hEvent );
	if( m_OverlappedWrite.hEvent != NULL ) CloseHandle( m_OverlappedWrite.hEvent );
	CloseHandle( m_hIDComDev );
	m_bOpened = FALSE;
	m_hIDComDev = NULL;
	return( TRUE );
}
BOOL CSerial::WriteCommByte( unsigned char ucByte )
{
	BOOL bWriteStat;
	DWORD dwBytesWritten;
	bWriteStat = WriteFile( m_hIDComDev, (LPSTR) &ucByte, 1, &dwBytesWritten, &m_OverlappedWrite );
	if( !bWriteStat && ( GetLastError() == ERROR_IO_PENDING ) ){
		if( WaitForSingleObject( m_OverlappedWrite.hEvent, 1000 ) ) dwBytesWritten = 0;
		else{
			GetOverlappedResult( m_hIDComDev, &m_OverlappedWrite, &dwBytesWritten, FALSE );
			m_OverlappedWrite.Offset += dwBytesWritten;
			}
		}
	return( TRUE );
}
int CSerial::SendData( const char *buffer, int size )
{
	if( !m_bOpened || m_hIDComDev == NULL ) return( 0 );
	DWORD dwBytesWritten = 0;
	int i;
	for( i=0; i<size; i++ ){
		WriteCommByte( buffer[i] );
		dwBytesWritten++;
		}
	return( (int) dwBytesWritten );
}
int CSerial::ReadDataWaiting( void )
{
	if( !m_bOpened || m_hIDComDev == NULL ) return( 0 );
	DWORD dwErrorFlags;
	COMSTAT ComStat;
	ClearCommError( m_hIDComDev, &dwErrorFlags, &ComStat );
	return( (int) ComStat.cbInQue );
}
int CSerial::ReadData( void *buffer, int limit )
{
	if( !m_bOpened || m_hIDComDev == NULL ) return( 0 );
	BOOL bReadStatus;
	DWORD dwBytesRead, dwErrorFlags;
	COMSTAT ComStat;
	ClearCommError( m_hIDComDev, &dwErrorFlags, &ComStat );
	if( !ComStat.cbInQue ) return( 0 );
	dwBytesRead = (DWORD) ComStat.cbInQue;
	if( limit < (int) dwBytesRead ) dwBytesRead = (DWORD) limit;
	bReadStatus = ReadFile( m_hIDComDev, buffer, dwBytesRead, &dwBytesRead, &m_OverlappedRead );
	if( !bReadStatus ){
		if( GetLastError() == ERROR_IO_PENDING ){
			WaitForSingleObject( m_OverlappedRead.hEvent, 2000 );
			return( (int) dwBytesRead );
			}
		return( 0 );
		}
	return( (int) dwBytesRead );
}

						