C# Chart Control serie is covered by custom label

Question

I'm using C# chart control to draw a nyquist plot. Now i want data points appear on the curve each time the user moves the mouse on it. So i used hit test method in GetToolTipText event.

private void BodePlot_GetToolTipText(object sender, ToolTipEventArgs e)
        {
            HitTestResult result = BodePlot.HitTest(e.X, e.Y);
            selectDataPoint = null;

            if (result.ChartElementType == ChartElementType.DataPoint)
                {
                    selectDataPoint = (DataPoint)result.Object;
                    e.Text = selectDataPoint.ToString();
                }
         {

The problem is only a part of the curve shows values, others don't. When i use e.Text = result.Object.ToString(); to get the object on which the mouse is pointing to, here what i found :

Instead of showing the data points, the text on tooltip show custom label. So i guess the reason is that the curve is covered by the labels of x and y axis.

The only solution that i found is disabling the x and y axis, with that everything works fine. But i want to keep those axes, so how can i make those labels hide under the curve.

Answer 1

Your analysis is likely correct. The way to go around this would be to provide HitTest() with the optional third argument which define the desired element type.

public HitTestResult HitTest (
int x,
int y,
ChartElementType requestedElement
)

This should return underlying data points even if other elements are overlapping them.