关于 procedure of object

procedure TForm1.BBB(I: Integer);begin  showmessage('BBB:' + IntToStr(I));end;procedure TForm1.CCC(I: Integer);begin  showmessage('CCC:' + IntToStr(I));end;procedure TForm1.Button1Click(Sender: TObject);  type    Taaa = procedure (i:integer) of object ;var  ap: Taaa;begin  ap := BBB;  ap(1);  ap := CCC;  ap(2);end;