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unit Unit1;
interface
uses
Windows;
type
TComPort = class
private
hFile: THandle;
public
constructor Create;
destructor Destroy; override;
function InitCom(BaudRate, PortNo: Integer; Parity: Char;
CommTimeOuts: TCommTimeouts): Boolean;
procedure CloseCom;
function ReceiveCom(var Buffer; Size: DWORD): Integer;
function SendCom(var Buffer; Size: DWORD): Integer;
function ClearInputCom: Boolean;
end;
implementation
uses
SysUtils;
constructor TComPort.Create;
begin
inherited;
CloseCom;
end;
destructor TComPort.Destroy;
begin
CloseCom;
inherited;
end;
function TComPort.InitCom(BaudRate, PortNo: Integer; Parity: Char;
CommTimeOuts: TCommTimeouts): Boolean;
var
FileName: string;
DCB: TDCB;
PortParam: string;
begin
result := FALSE;
FileName := 'Com' + IntToStr(PortNo); {имя файла}
hFile := CreateFile(PChar(FileName),
GENERIC_READ or GENERIC_WRITE, 0, nil,
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
if hFile = INVALID_HANDLE_VALUE then
exit;
//установка требуемых параметров
GetCommState(hFile, DCB); //чтение текущих параметров порта
PortParam := 'baud=' + IntToStr(BaudRate) + ' parity=' + Parity +
' data=8 stop=1 ' +
'octs=off';
if BuildCommDCB(PChar(PortParam), DCB) then
begin
result := SetCommState(hFile, DCB) and
SetCommTimeouts(hFile, CommTimeOuts);
end;
if not result then
CloseCom;
end;
procedure TComPort.CloseCom;
begin
if hFile < > INVALID_HANDLE_VALUE then
CloseHandle(hFile);
hFile := INVALID_HANDLE_VALUE;
end;
function TComPort.ReceiveCom(var Buffer; Size: DWORD): Integer;
var
Received: DWORD;
begin
if hFile = INVALID_HANDLE_VALUE then
raise Exception.Create('Не открыта запись в Com порт');
if ReadFile(hFile, Buffer, Size, Received, nil) then
begin
Result := Received;
end
else
raise Exception.Create('Ошибка приема данных: ' + IntToStr(GetLastError));
end;
function TComPort.SendCom(var Buffer; Size: DWORD): Integer;
var
Sended: DWORD;
begin
if hFile = INVALID_HANDLE_VALUE then
raise Exception.Create('Не открыта запись в Com порт');
if WriteFile(hFile, Buffer, Size, Sended, nil) then
begin
Result := Sended;
end
else
raise Exception.Create('Ошибка передачи данных: ' + IntToStr(GetLastError));
end;
function TComPort.ClearInputCom: Boolean;
begin
if hFile = INVALID_HANDLE_VALUE then
raise Exception.Create('Не открыта запись в Com порт');
Result := PurgeComm(hFile, PURGE_RXCLEAR);
end;
end.
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