www.gusucode.com > vc++ 计算机串口通信的软件设计与实现 > vc++ 计算机串口通信的软件设计与实现/Serial.cpp
// 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 ); }