Why checking WizardForm for null in inno setup is not working?

Question

Why is this not working?

if WizardForm <> nil then
  WizardForm.StatusLabel.Caption := 'blah'
else
  Log('WizardForm not initialized yet!');

I get this exception:

Runtime Error (at 15:118):
Internal error: An attempt was made to access WizardForm before it has been created.

I know that WizardForm is not yet initialized, that's why I check for nil, the check is not working! What am I doing wrong here?

Answer 1

That happens to every access of the WizardForm variable including the check, if it's assigned. Simply move your code from InitializeSetup event to InitializeWizard.

Answer 2

Is there any other way to check for null?

How about this:

function IsWizardFormCreated(): Boolean;
begin
  Result := True;
  try
    WizardForm;
  except
    Result := False;
  end;
end;