All components in Delphi are objects, so Create and Destroy have to be used for creating and destroying of the component at runtime. A problem with TTabbedNotebook in a correct placement of control on appropriate page. The process of adding controls to a TNotebook is almost exactly the same as that for TTabbedNotebook - only the page class type is TPage instead of TTabPage. So we can do:
uses Tabnotbk; ... procedure TForm1.Button1Click(Sender: TObject); var TabPage: TTabPage; Button: TButton; begin with TabbedNotebook1 do TabPage:=TTabPage(Pages.Objects[PageIndex]); Button:=TButton.Create(TabPage); try with Button do begin Parent:=TabPage; Left:=Random(TabPage.ClientWidth-Width); Top:=Random(TabPage.ClientHeight-Height); end; except Button.Free; end; end;