Delphi: Detect when a new form has been created

Question

I\'d like to detect when a new form has been created.

Now I use the Screen.ActiveFormChange event and check for new forms in Screen.CustomForms

Answer 1

Track Screen.CustomFormCount in Application.OnIdle:

  private
    FPrevFormCount: Integer;
  end;

procedure TForm1.ApplicationEvents1Idle(Sender: TObject; var Done: Boolean);
begin
  if Screen.CustomFormCount > FPrevFormCount then
    Caption := Caption + ' +1';
  if Screen.CustomFormCount <> FPrevFormCount then
    FPrevFormCount := Screen.CustomFormCount;
end;

procedure TForm1.TestButton1Click(Sender: TObject);
begin
  TForm2.Create(Self).Show;
end;

procedure TForm1.TestButton2Click(Sender: TObject);
begin
  ShowMessage('Also trackable?');  // Yes!
end;

procedure TForm1.TestButton3Click(Sender: TObject);
begin
  OpenDialog1.Execute; // Doesn't update Screen.CustomFormCount
end;

Native dialogs managed and shown by Windows (TOpenDialog, TFontDialog, etc...) are created apart from the VCL and to track them also, you need a hacking unit. Try this one then.