Hi Noah,

We just tested a similar case with the following code, but we were not able to reproduce the problem. The DataPointIndex seems to be reported properly regardless of whether the data labels are visible or not. Are there any particular settings that we are missing?

   public partial class Form1 : Form
   {
      public Form1()
      {
         InitializeComponent();
      }

      private void Form1_Load(object sender, EventArgs e)
      {
         NBoxAndWhiskersSeries bw = new NBoxAndWhiskersSeries();
         bw.DataLabelStyle.Visible = false;
         bw.UseXValues = true;

         nChartControl1.Charts[0].Series.Add(bw);
         nChartControl1.MouseMove += new MouseEventHandler(nChartControl1_MouseMove);

         AddBox(bw, 0, 100, 203, 60, 230);
         AddBox(bw, 1, 130, 230, 50, 250);
         AddBox(bw, 2, 110, 200, 60, 220);
         AddBox(bw, 3, 90, 220, 40, 230);
         AddBox(bw, 4, 110, 210, 30, 220);
         AddBox(bw, 5, 100, 205, 70, 230);
      }

      void AddBox(NBoxAndWhiskersSeries bw, double x, double lb, double ub, double lw, double uw)
      {
         bw.LowerBoxValues.Add(lb);
         bw.UpperBoxValues.Add(ub);            
         bw.LowerWhiskerValues.Add(lw);
         bw.UpperWhiskerValues.Add(uw);
         bw.XValues.Add(x);
      }

      void nChartControl1_MouseMove(object sender, MouseEventArgs e)
      {
         NHitTestResult hitTest = nChartControl1.HitTest(e.X, e.Y);

         if ((hitTest.ChartElement == ChartElement.DataPoint) && (hitTest.Series.GetSeriesType() == SeriesType.BoxAndWhiskers))
            this.Text = hitTest.DataPointIndex.ToString();
         else
            this.Text = string.Empty;
      }
   }

Best Regards,
Nevron Support Team

I have added custom code to update a tooltip as the user mouses over data points within a series, however the value for DataPointIndex is wrong unless I am also showing data labels, which is ugly and seems like bug.

private void ChartControl_OnMouseMove(object sender, MouseEventArgs e)
{
NHitTestResult hitTest = _ChartControl.HitTest(e.X, e.Y);

if (hitTest.ChartElement == ChartElement.DataPoint)
{
var tip = new SuperToolTip() { AllowHtmlText = DefaultBoolean.True };

if (hitTest.Series.Name != "Line Series" && hitTest.Series.Name != "Point Series")
{
var title = tip.Items.AddTitle(hitTest.Series.Name);
}

//title.Appearance.TextOptions.HAlignment = HorzAlignment.Center;

switch (hitTest.Series.GetSeriesType())
{
//case SeriesType.Line:
// {
// var series = (NLineSeries)hitTest.Series;
// break;
// }

case SeriesType.BoxAndWhiskers:
{
var series = (NBoxAndWhiskersSeries) hitTest.Series;
tip.Items.Add("Index: " + hitTest.DataPointIndex);
tip.Items.AddSeparator();
tip.Items.Add("Low: " + ((double)series.LowerBoxValues[hitTest.DataPointIndex]).ToString(Model.DataFormatString));
tip.Items.Add("High: " + ((double)series.UpperBoxValues[hitTest.DataPointIndex]).ToString(Model.DataFormatString));
tip.Items.Add("Mean: " + ((double)series.AverageValues[hitTest.DataPointIndex]).ToString(Model.DataFormatString));
tip.Items.Add("Median: " + ((double)series.MedianValues[hitTest.DataPointIndex]).ToString(Model.DataFormatString));

break;
}

default:
{
if (hitTest.Series is NSeries)
{
var series = hitTest.Series as NSeries;

tip.Items.Add("Value: " + ((double) series.Values[hitTest.DataPointIndex]).ToString(Model.DataFormatString));
}

break;
}
}

var showArgs = new ToolTipControllerShowEventArgs() { SuperTip = tip };

_ChartControl.Widget.KFrame.ToolTipController.ShowHint(showArgs);
}
else
{
_ChartControl.Widget.KFrame.ToolTipController.HideHint();
}

}