Unit Unit1;

Interface

Uses

  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,

  StdCtrls;

Type

   TForm1 = Class(TForm)

      ReleaseScrollLockBtn: TButton;

      SetScrollLockBtn: TButton;

      Procedure SetScrollLockBtnClick(Sender: TObject);

      Procedure ReleaseScrollLockBtnClick(Sender: TObject);

   Private

      { Private declarations }

   Public

      { Public declarations }

   End;

Var

   Form1 : TForm1;

Implementation

{$R *.DFM}

//----------------------------------------------------------------------

// The Numlock key can be pressed this way under NT but NOT under W95!

// The ScrollLock and CapsLock can be pressed this way under NT and W95

// as well.

// You can also simulate a PrintScreen (SnapShot).

// See the Delphi help file for soft-pressing this key.

// (Set the blinking cursor in the word: "keybd_event" and press: "F1")

//----------------------------------------------------------------------

Procedure SetNumLock(Bo : Boolean);

Var

   keyState : TKeyBoardState;

Begin

GetKeyboardstate(keyState);

// keyState[VK_SCROLL] = 0 means the led is off

// keyState[VK_SCROLL]  0 means the led is on

If ( (Bo = True) and (keyState[VK_SCROLL] = ) ) or

   ( (Bo = False) and (keyState[VK_SCROLL]  ) ) then

      Begin

      // Simulate a depress

      keybd_event(VK_SCROLL,,KEYEVENTF_EXTENDEDKEY,);

      // Simulate a release

      keybd_event(VK_SCROLL,,KEYEVENTF_EXTENDEDKEY + KEYEVENTF_KEYUP,);

      End;

End;

//----------------------------------------------------------------------

Procedure TForm1.SetScrollLockBtnClick(Sender: TObject);

Begin

SetNumLock(TRUE);

End;

//----------------------------------------------------------------------

Procedure TForm1.ReleaseScrollLockBtnClick(Sender: TObject);

Begin

SetNumLock(FALSE);

End;

//----------------------------------------------------------------------

End. {of Unit1}

//======================================================================