Советы по Delphi. Версия 1.4.3 от 1.1.2001

 private
 FPort:TPort;
 FBaudRate:TBaudRate;
 FParity:TParity;
 FDataBits:TDataBits;
 FStopBits:TStopBits;
 FReadBufferSize:Word;
 FWriteBufferSize:Word;
 FRxFull:Word;
 FTxLow:Word;
 FEvents:TCommEvents;
 FOnEvent:TNotifyEventEvent;
 FOnReceive:TNotifyReceiveEvent;
 FOnTransmit:TNotifyTransmitEvent;
 FWindowHandle:hWnd;
 hComm:Integer;
 HasBeenLoaded:Boolean;
 Error:Boolean;
 procedure SetPort(Value:TPort);
 procedure SetBaudRate(Value:TBaudRate);
 procedure SetParity(Value:TParity);
 procedure SetDataBits(Value:TDataBits);
 procedure SetStopBits(Value:TStopBits);
 procedure SetReadBufferSize(Value:Word);
 procedure SetWriteBufferSize(Value:Word);
 procedure SetRxFull(Value:Word);
 procedure SetTxLow(Value:Word);
 procedure SetEvents(Value:TCommEvents);
 procedure WndProc(var Msg:TMessage);
 procedure DoEvent;
 procedure DoReceive;
 procedure DoTransmit;
 protected
 procedure Loaded; override;
 public
 constructor Create(AOwner:TComponent); override;
 destructor Destroy; override;
 procedure Write(Data:PChar; Len:Word);
 procedure Read(Data:PChar; Len:Word);
 function IsError:Boolean;
 published
 property Port:TPort read FPort write SetPort default PortDefault;
 property BaudRate:TBaudRate read FBaudRate write SetBaudRate default BaudRateDefault;
 property Parity:TParity read FParity write SetParity default ParityDefault;
 property DataBits:TDataBits read FDataBits write SetDataBits default DataBitsDefault;
 property StopBits:TStopBits read FStopBits write SetStopBits default StopBitsDefault;
 property WriteBufferSize:Word read FWriteBufferSize write SetWriteBufferSize default WriteBufferSizeDefault;
 property ReadBufferSize:Word read FReadBufferSize write SetReadBufferSize default ReadBufferSizeDefault;
 property RxFullCount:Word read FRxFull write SetRxFull default RxFullDefault;
 property TxLowCount:Word read FTxLow write SetTxLow default TxLowDefault;
 property Events:TCommEvents read FEvents write SetEvents default EventsDefault;
 property OnEvent:TNotifyEventEvent read FOnEvent write FOnEvent;
 property OnReceive:TNotifyReceiveEvent read FOnReceive write FOnReceive;
 property OnTransmit:TNotifyTransmitEvent read FOnTransmit write FOnTransmit;
 end;

procedure Register;

implementation

procedure TComm.SetPort(Value:TPort);
const CommStr:PChar='COM1:';
begin
 FPort:=Value;
 if (csDesigning in ComponentState) or (Value=tptNone) or (not HasBeenLoaded) then exit;
 if hComm>=0 then CloseComm(hComm);
 CommStr[3]:=chr(48+ord(Value));
 hComm:=OpenComm(CommStr,ReadBufferSize,WriteBufferSize);
 if hComm<0 then begin
 Error:=True;
 exit;
 end;
 SetBaudRate(FBaudRate);
 SetParity(FParity);
 SetDataBits(FDataBits);
 SetStopBits(FStopBits);
 SetEvents(FEvents);
 EnableCommNotification(hComm,FWindowHandle,FRxFull,FTxLow);
end;

procedure TComm.SetBaudRate(Value:TBaudRate);