protected override void OnRender(ChartControl chartControl, ChartScale chartScale)
{
  base.OnRender(chartControl, chartScale);
  // loop through only the rendered bars on the chart
  for(int barIndex = ChartBars.FromIndex; barIndex <= ChartBars.ToIndex; barIndex++)
  {
    // get the low price at the selected bar index value
    double lowPrice = Bars.GetLow(barIndex);
    Print("Bar #" + barIndex + " low price is " + lowPrice);
  }
}