Question

I have code in CurPageChanged that adds a button to the license window. My CurPageChanged starts like this:

procedure CurPageChanged(CurPageID: Integer);
var Button123 TButton;
begin
  if CurPageID = wpLicense then begin
    Button123 := TButton.Create(WizardForm.LicenseMemo.Parent);

My question is wouldn’t that create a button each time the page is changed to the wpLicense page? So if a user clicks past the license dialog, then goes back to it, wouldn’t that create another button? How can I ensure that only one button is created? What I’m looking for is the most appropriate procedure from which to add a control –once– to an existing wp. Thanks

Answer 1

My question is wouldn’t that create a button each time the page is changed to the wpLicense page? So if a user clicks past the license dialog, then goes back to it, wouldn’t that create another button?

Yes, it would create multiple buttons each time. Because the pages do not get destroyed, the controls on them do not get destroyed. But you can actually take advantage of that fact to create a single control and then show/hide it when necessary.

To start, modify the InitializeWizard method, which is called only once before the wizard is displayed. Create the button in here, like so:

procedure InitializeWizard();
var
  MyButton: TButton;
begin
  MyButton := TButton.Create(WizardForm.LicenseMemo.Parent);
  MyButton.Parent := WizardForm.LicenseMemo.Parent;
  MyButton.Top := 0;
  MyButton.Left := 0;
  MyButton.Caption := 'My Custom Button';
  ...
end;