[[AgustinOrtu]]

Habria que ver, el OnReorderButton se dispara despues de alterar el orden

Código Delphi [-]
procedure TButtonGroup.DoReorderButton(const OldIndex, NewIndex: Integer);
var
  OldIndexID: Integer;
begin
  FIgnoreUpdate := True;
  try
    if FItemIndex <> -1 then
      OldIndexID := Items[FItemIndex].ID
    else
      OldIndexID := -1;
    FButtonItems.Items[OldIndex].Index := NewIndex;
    if OldIndexID <> -1 then
      FItemIndex := Items.FindItemID(OldIndexID).Index;
  finally
    FIgnoreUpdate := False;
  end;
  if HandleAllocated then
    RedrawWindow(Handle, nil, 0, RDW_INVALIDATE or RDW_UPDATENOW);
  if Assigned(FOnReorderButton) then
    FOnReorderButton(Self, OldIndex, NewIndex);
end;