KB10773 - How to prevent from moving the layer in the legend control?

This can be done by overriding the TGIS_ControlLegend.OrderChange event. For example, in Delphi:

procedure TForm1.LegendOrderChange(Sender: TObject);
begin
  if MyLayer.ZOrder <> 0 then begin
    MyLayer.Zorder := 0 ;
    Legend.Update ;
  end ;
end;