change keypressed

hi experts
i want to know how i can traping key pressed and void or chang it. please help me by Source Code. Thanks
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Mike LittlewoodEngineerCommented:
For voiding a key

procedure TForm1.Edit1KeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
  Key := 0
Mike LittlewoodEngineerCommented:
Do you want the keydown function to be application wide, or per component.
If per component then you need to write one for each.
If application wide, make sure you set the value of the main form of your application "KeyPreview = True" in the object inspector.
Mike LittlewoodEngineerCommented:
For changing the key I would probably do it on KeyPress event of the components

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
  if key = 'a' then
    key := 'b'
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mahdiparakAuthor Commented:
thanks but i want Keyboard hook and work my application with other application such az MS Word
A. Cristian CsikiSenior Security AdministratorCommented:

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