SPCOMM的方法

SPCOMM的方法

METHOD ======     procedure StartComm         Start a communication for this comm port.         If failure, raise ECommsError exception and ECommsError.Message contain         following string:             'This serial port already opened'             'Error opening serial port'             'File handle is not a comm handle'             'Cannot setup comm buffer'             'Unable to create event'             'Unable to create read thread'             'Unable to create write thread'     procedure StopComm         Stop and end all communication threads for this comm port.         No any return.     function WriteCommData( pDataToWrite: PChar;                             dwSizeofDataToWrite: Word ): Boolean         Send a String to the Write Thread to be written to the Comm.         This subroutine will return immediately. The send operation will         do in background.         Parameters:             pszStringToWrite       - string to Write to Comm port.             nSizeofStringToWrite - length of pszStringToWrite.         Return:             TRUE : if the PostMessage to write thread is successful.             FALSE: if PostMessage fails or Write thread doesn't exist.     function GetModemState : DWORD;        Get and return the modem state right now. They are the state of modem        input pin from MSR.        The return value can be one or more of the following codes:         Value         Meaning         ----------    -----------------------------------------------------------         MS_CTS_ON     The CTS (clear-to-send) signal is on.         MS_DSR_ON     The DSR (data-set-ready) signal is on.         MS_RING_ON    The ring indicator signal is on.         MS_RLSD_ON    The RLSD (receive-line-signal-detect) signal is on.         The function fails if the hardware does not support the         control-register values. EVENT HANDLER =============     OnReceiveData : procedure (Sender: TObject;                                Buffer: Pointer;                                BufferLength: Word) of object         When           1. The input buffer contains received data and           2. more than a limit size or           3. read time-out         the event handler is called         Sender : point to TComm object which raise this call         Buffer : the buffer which contains received data         BufferLength : the size of received data in Buffer     OnReceiveError : procedure(Sender: TObject; EventMask : DWORD) of object         When error happend during receiving, the event handler is called.         Sender : point to TComm object which raise this call         EventMask : the value get from ClearCommError in 'HandleCommEvent'                     A 32-bit variable to be filled with a mask indicating the                     type of error. This parameter can be one or more of the                     following error codes:         Value         Meaning         ----------    -----------------------------------------------------------         CE_BREAK      The hardware detected a break condition. (no support now)         CE_DNS        Windows 95 only: A parallel device is not selected.         CE_FRAME      The hardware detected a framing error.         CE_IOE        An I/O error occurred during communications with the device.         CE_MODE       The requested mode is not supported, or the hFile parameter                     is invalid. If this value is specified, it is the only                     valid error.         CE_OOP        Windows 95 only: A parallel device signaled that it is out                     of paper.         CE_OVERRUN    A character-buffer overrun has occurred. The next character                     is lost.         CE_PTO        Windows 95 only: A time-out occurred on a parallel device.         CE_RXOVER     An input buffer overflow has occurred. There is either no                     room in the input buffer, or a character was received after                     the end-of-file (EOF) character.                     (second condition is impossible happened under Win32)         CE_RXPARITY The hardware detected a parity error. (no support)         CE_TXFULL     The application tried to transmit a character, but the                     output buffer was full. (no support)     OnRequestHangup: procedure(Sender: TObject) of object;         When the program is terminated abnormally, the event handler is         called.     OnModemStateChange : procedure(Sender: TObject; ModemEvent : DWORD) of object         When Modem's RLSD(CD) change state (HIGH<->LOW) or the ring indicator         signal is detected, this event handler is         called.         Sender : point to TComm object which raise this call         ModemEvent : A 32-bit variable to be filled with a mask indicating                      what made this call. This parameter can be one or more                      of the following codes:         Value         Meaning         ----------    -----------------------------------------------------------         ME_CTS        The CTS (clear-to-send) signal has changed state.                     (support in future, not support now)         ME_DSR        The DSR (data-set-ready) signal has changed state.                     (support in future, not support now)         ME_RING       The ring indicator signal was detected.         ME_RLSD       The RLSD (receive-line-signal-detect) signal has changed                     state.         Call GetModemState method to get the real state of modem state. LEGALITIES ========== This component is totally free (along with source code).