Code:

procedure TForm1.FormCreate(Sender: TObject);

begin

{This only works for classes registered using RegisterClass}

RegisterClasses([TButton, TForm]);

end;

procedure TForm1.Button1Click(Sender: TObject);

var

CRef: TPersistentClass;

PTI: PTypeInfo;

AControl: TControl;

begin

CRef := GetClass('TButton');

if CRef <> nil then

begin

   AControl := TControl(TControlClass(CRef).Create(Self));

   with AControl do

   begin

     Parent := Self;

     Width := 50;

     Height := 30;

   end;

   Inc(Id);

end

else

   MessageDlg('No such class', mtWarning, [mbOk], 0);

end;