[advanced_delphi] Subcomponent of TWincontrol scroll too...

[neomavez]

I need to make a component that descends from TTreeView. I want to add
a button as subcomponent.

constructor TMyTree.Create(AOwner: TComponent);
begin
  inherited;

    bt    := TButton.Create(Self) ;
    bt.Parent    := Self ;
    btAll.SetSubComponent(True)   ;

    btAll.Height  := x  ;
    etc, etc etc

end;

Everything works perfect, but when TTReeView Scroll, the button Scroll
too. I would like to remain equidistant from the top edge.
How should I deal with this problem? The Button Parent should be the
same Parent of "Self" (i.e. the Form) ?
I would thank you very much for a little clue to continue. I hope you
understand my english.

TIA