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Trapping for Ctrl-F4

keithcsl
keithcsl asked
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Last Modified: 2010-04-06
Hi

I have a MDI applicatin with several child forms. How do I prevent the user from pressing Ctrl-F4 to close the child for (similarly Ctrl-F6 to switch between forms)?

Regards
Keith
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Author

Commented:
victornet

Hi, have you tried your code and got it going? I wrote the exact same code but have failed to trap it. I might be doing it wrong:

In the OnCloseQuery event:
  if flgCannotClose = True then
    CanClose := False;

In the KeyDown event of the form
  if (Shift = [ssctrl]) AND (key = VK_F4) then
    flgCannotClose = True;

Regards
Keith

Author

Commented:
Victornet

I have noticed that the OnCloseQuery is called before the OnKeyDown, that's why I can't trap the Ctrl-F4

It works for Ctrl-F3, etc

Regards
Keith
Hello Keith =)

Here is what you do......
-----------
var
  flgCannotClose : boolean = False;
procedure TForm1.FormKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  flgCannotClose := True = (Shift = [ssctrl]) AND (key = VK_F4);
end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
   if flgCannotClose = True then
     Action := caNone;
end;

procedure TForm1.FormKeyUp(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  flgCannotClose := False;
end;
----------
Regards,
Viktor Ivanov

Author

Commented:
Oh boy, I think it must have been the late nights that have made me a little blind.

Viktornet, thanks to your code above, I have just realised that to avoid the forms from closing, all I have to do is to set
  Action := caNone
in the OnClose event of the form

Thanks a lot

Regards
Keith
No prob :-)

Regards,
Viktor Ivanov
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