Hi Alexandr,

The following code snippet shows how to find the closest axis tick value (provided that the step is fixed):

  private void Form1_Load(object sender, EventArgs e)
  {
   NChart chart = nChartControl1.Charts[0];

   NBarSeries bar = new NBarSeries();

   bar.Values.Add(10);
   bar.Values.Add(20);
   bar.Values.Add(30);

   chart.Series.Add(bar);

   NLinearScaleConfigurator scaleY = chart.Axis(StandardAxis.PrimaryY).ScaleConfigurator as NLinearScaleConfigurator;

   scaleY.MajorTickMode = MajorTickMode.CustomStep;
   scaleY.CustomStep = 5;

   nChartControl1.MouseDown += new MouseEventHandler(nChartControl1_MouseDown);
  }

  void nChartControl1_MouseDown(object sender, MouseEventArgs e)
  {
   NHitTestResult result = nChartControl1.HitTest(e.X, e.Y);

   if (result.Axis != null && result.Axis.AxisId == (int)StandardAxis.PrimaryY)
   {
    NViewToScale1DTransformation viewToScale = new NViewToScale1DTransformation(nChartControl1.View.Context, nChartControl1.Charts[0], (int)StandardAxis.PrimaryY, (int)StandardAxis.PrimaryX);

    double scaleValue = 0;
    if (viewToScale.Transform(new NPointF(e.X, e.Y), ref scaleValue))
    {
     double tickValue = (int)Math.Round(scaleValue / 5) * 5;

     MessageBox.Show("Closest tick value[" + tickValue.ToString() + "]");
    }
   }
  }

Hope this helps - let us know if you meet any problems or have any questions.

Best Regards,
Nevron Support Team

this pseudo code looks perfect) but how to implement this? I mean FindLabelClosestToPoint(point). I know the NAxis object - how I detect what scale label was clicked?

Hi Alexandr,

The axis does not distinguish between custom and automatic labels for hit testing purposes. You can implement a workaround that basically returns the label whose value is closest to the transformed viewport to scale coordinate on that axis. In pseudo code this will look like:

currentChartElemnt = chart.HitTest(point);

if (currentChartElement is axis)
{
point = ConvetPointFromViewToScale(point)

FindLabelClosestToPoint(point);
}

Let us know if you meet any problems or have any questions.

Best Regards,
Nevron Support Team

I need to detect clicks for axis labels. For example I have X axis with labels "1,2,3,4... etc". I want to know when user click on "1" or "2" label and so on. I tried HitTest function, it correct returns that Axis object is clicked, but there is no info which label was clicked. Could you help here?