rite.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_hComDev );
return FALSE;
}

m_bOpened = TRUE;

return m_bOpened;

}

int CSerial::InBufferCount( void )
{

if( !m_bOpened || m_hComDev == NULL ) return( 0 );

DWORD dwErrorFlags;
COMSTAT ComStat;

ClearCommError( m_hIDComDev, &dwErrorFlags, &ComStat );

return (int)ComStat.cbInQue;

}

DWORD CSerial::ReadData( void *buffer, DWORD dwBytesRead)
{

if( !m_bOpened || m_hComDev == NULL ) return 0;

BOOL bReadStatus;
DWORD dwErrorFlags;
COMSTAT ComStat;

ClearCommError( m_hComDev, &dwErrorFlags, &ComStat );
if( !ComStat.cbInQue ) return 0;

dwBytesRead = min(dwBytesRead,(DWORD) ComStat.cbInQue);

bReadStatus = ReadFile( m_hComDev, buffer, dwBytesRead, &dwBytesRead, &m_OverlappedRead );
if( !bReadStatus ){
if( GetLastError() == ERROR_IO_PENDING ){
WaitForSingleObject( m_OverlappedRead.hEvent, 2000 );
return dwBytesRead;
}
return 0;
}

return dwBytesRead;

}

DWORD CSerial::SendData( const char *buffer, DWORD dwBytesWritten)
{

if( !m_bOpened || m_hComDev == NULL ) return( 0 );

BOOL bWriteStat;

bWriteStat = WriteFile( m_hComDev, buffer, dwBytesWritten, &dwBytesWritten, &m_OverlappedWrite );
if( !bWriteStat){
if ( GetLastError() == ERROR_IO_PENDING ) {
WaitForSingleObject( m_OverlappedWrite.hEvent, 1000 );
return dwBytesWritten;
}
return 0;
}
return dwBytesWritten;

}



　　上述函数基本实现串口的打开，读写操作。本文章略去该串口类的说明和关闭函数。读者应该能将这些内容写完。接下来，你就可以在你的程序中调用该串口类了。关于本文有任何疑问，请与作者联系。

　　本文参考文献：MSDN 1999, Microsoft Corp