IOCTL von C nach Delphi portieren

[Robert Marquardt]

So ist es sauberer und einfacher.

Delphi-Quellcode:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls;

type
  TfrmMain = class(TForm)
    gboxWatchdog: TGroupBox;
    gboxIOOperations: TGroupBox;
    Button1: TButton;
    Edit1: TEdit;
    procedure Button1Click(Sender: TObject);
  public
  end;

type
  PWDTPARAM = ^WDTPARAM;
  WDTPARAM = record
    timeout: Byte;
    data_b: Byte;
  end;

const
     WDT_TYPE = $88B9; //35001;

     WDT_DEVICE   = '\\.\WDT_DEVICE';
     WDT_DEVICE_NAME = '\Device\WDT_DEVICE';
     WDT_DOS_DEVICE_NAME = '\DosDevices\WDT_DEVICE';

     IOCTL_SYS_WDT_SET_TIMEOUT = DWORD((WDT_TYPE shl 16) or (2 shl 14) or ($800 shl 2) or 0);
     IOCTL_SYS_WDT_START = DWORD((WDT_TYPE shl 16) or (2 shl 14) or ($801 shl 2) or 0);
     IOCTL_SYS_WDT_STOP   = DWORD((WDT_TYPE shl 16) or (2 shl 14) or ($802 shl 2) or 0);
     IOCTL_SYS_WDT_RESTART = DWORD((WDT_TYPE shl 16) or (2 shl 14) or ($803 shl 2) or 0);
     IOCTL_SYS_DIO_READ   = DWORD((WDT_TYPE shl 16) or (2 shl 14) or ($804 shl 2) or 0);
     IOCTL_SYS_DIO_WRITE = DWORD((WDT_TYPE shl 16) or (2 shl 14) or ($805 shl 2) or 0);

var
  frmMain: TfrmMain;

implementation

{$R *.DFM}

procedure TfrmMain.Button1Click(Sender: TObject);
var
  hDIO: THandle;
  cParam: WDTPARAM;
  nReturn: DWORD;
begin
     hDIO := CreateFile(WDT_DEVICE, GENERIC_READ OR GENERIC_WRITE, FILE_SHARE_READ OR
                    FILE_SHARE_WRITE, NIL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL OR
                    FILE_FLAG_NO_BUFFERING, 0);

     if hDIO <> INVALID_HANDLE_VALUE then
     begin
          cParam.timeout := 0;
          cParam.data_b := Byte(StrToIntDef('$' + Edit1.Text, 0));
          DeviceIoControl(hDIO, IOCTL_SYS_DIO_WRITE, @cParam, SizeOf(cParam), nil, 0, nReturn, nil);
          CloseHandle(hDIO);
     end
     else begin
          MessageDlg('Fehler, kein (gültiges) Handle!', mtWarning, [mbOK], 0);
     end;
end;

end.

Lokale Variablen sind besser. Dazu muss dann aber das Element timeout explizit gesetzt werden. Bei globalen Variablen wird es implizit auf 0 gesetzt, aber bei lokalen Variablen ist der Inhalt Zufall.