class CSerialPort
{                                                         
public:
    // contruction and destruction
    CSerialPort();
    virtual        ~CSerialPort();

    // port initialisation                                            
    BOOL        InitPort(CWnd* pPortOwner, 
　　　　　　　　　　　　　　UINT portnr = 1,
　　　　　　　　　　　　　　UINT baud = 19200, 
　　　　　　　　　　　　　　char parity = ‘N‘, 
　　　　　　　　　　　　　　UINT databits = 8, 
　　　　　　　　　　　　　　UINT stopsbits = 1, 
　　　　　　　　　　　　　　DWORD dwCommEvents = EV_RXCHAR | EV_CTS, 
　　　　　　　　　　　　　　UINT nBufferSize = 512);

    // start/stop comm watching
    BOOL        StartMonitoring();
    BOOL        RestartMonitoring();
    BOOL        StopMonitoring();

    DWORD        GetWriteBufferSize();
    DWORD        GetCommEvents();
    DCB            GetDCB();

    void        WriteToPort(char* string);

protected:
    // protected memberfunctions
    void        ProcessErrorMessage(char* ErrorText);
    static UINT    CommThread(LPVOID pParam);
    static void    ReceiveChar(CSerialPort* port, COMSTAT comstat);
    static void    WriteChar(CSerialPort* port);

    // thread
    CWinThread*            m_Thread;

    // synchronisation objects
    CRITICAL_SECTION    m_csCommunicationSync;
    BOOL                m_bThreadAlive;

    // handles
    HANDLE                m_hShutdownEvent;
    HANDLE                m_hComm;
    HANDLE                m_hWriteEvent;

    // Event array. 
    // One element is used for each event. There are two event handles for each port.
    // A Write event and a receive character event which is located in the overlapped structure (m_ov.hEvent).
    // There is a general shutdown when the port is closed. 
    HANDLE                m_hEventArray[3];

    // structures
    OVERLAPPED            m_ov;
    COMMTIMEOUTS        　m_CommTimeouts;
    DCB                   m_dcb;

    // owner window
    CWnd*                m_pOwner;

    // misc
    UINT                m_nPortNr;
    char*                m_szWriteBuffer;
    DWORD                m_dwCommEvents;
    DWORD                m_nWriteBufferSize;
};