TPanel and KeyDown

[Gürcan YÜCEL]

Hi,
Im trying to write something like designer. (like delphi form design) I need
different kind of components in a single panel. I created a class inherited
from a TPanel. When it gets focuse I need to catch key events. Here is the
simplified class;
///
interface
TDataField = Class(TPanel)
Protected
Procedure KeyDown(Sender: TObject; var Key: Word;Shift:
TShiftState);
public
constructor Create(aOwner: TComponent); override;
destructor Destroy;Virtual;

implementation

constructor TDataField.Create(aOwner: TComponent);
begin
inherited Create(aOwner);
Self.OnKeydown:=KeyDown;
end;

destructor TDataField.Destroy;
begin
end;

Procedure TDataField.KeyDown(Sender: TObject; var Key: Word;Shift:
TShiftState);
Begin
if Shift=[ssShift] then
if key=VK_UP then Self.Top:=Self.Top-2;
end;

I used TPanel, because Im putting a label and for example editbox
dynamically. Here is the problem;

KeyDown event catchs the key strokes except arrow keys.(Imean
VK_UP,DOWN,LEFT and Right. What is the problem? Why I cant use them? I can
use all other keys. Is it true to use TPanel? or I had to use TWinControl or
something like that? I tried with TWinControl but the result is same.

Thanks.

Gürcan YÜCEL

[Florent Ouchet]

You have to catch the WM_GETDLGCODE message and return a set or these values
:

DLGC_BUTTON Button.
DLGC_DEFPUSHBUTTON Default push button.
DLGC_HASSETSEL EM_SETSEL messages.
DLGC_RADIOBUTTON Radio button.
DLGC_STATIC Static control.
DLGC_UNDEFPUSHBUTTON Non-default push button.
DLGC_WANTALLKEYS All keyboard input.
DLGC_WANTARROWS Direction keys.
DLGC_WANTCHARS WM_CHAR messages.
DLGC_WANTMESSAGE All keyboard input (the application passes this
message in the MSG structure to the control).
DLGC_WANTTAB TAB key.

(from the platform SDK of microsoft)

I think you have to return DLGC_WANTALLKEYS or DLGC_WANTARROWS. Or if you
don't want the char keys just return DLGC_WANTARROWS.

Regards

Florent

"Gürcan YÜCEL" <gyu...@g-gsoft.com> a écrit dans le message de
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