Question

procedure TMainForm.FormDestroy(Sender: TObject);
var
  Registry: TRegistry;
begin
  Registry := TRegistry.Create;
  try
    Registry.RootKey := HKEY_CURRENT_USER;
    if Registry.OpenKey('...', True) then
    begin
      Registry.WriteInteger('MainLeft', Self.Left);
      Registry.CloseKey;
    end;
  finally
    Registry.Free;
  end;
end;

Similar code works for FormCreate, but not when the application is closed (i.e. nothing is saved to the registry). What am I missing?

The ‘…’ stands for the registry key name. Since it works for FormCreate, I don’t think it’s an issue.

If I add MainForm.Destroy to the program code:

begin
  Application.Initialize;
  Application.CreateForm(TMainForm, MainForm);
  Application.Run;
  MainForm.Destroy;
end.

nothing changes. If I also set FormDestroy as MainForm’s OnDestroy event, I get “Access violation” error upon closing the application.

Answer 1

Try TMainForm.OnCloseQuery instead:

http://delphi.about.com/od/formsdialogs/a/delphiformlife.htm