Hit Testing Axis Elements

In This Topic

Hit testing of axis elements is achieved in a slightly different manner than with ordinary chart objects. The reason for this is that one element in the axis description may result in several visual elements - for example the major tick style in the axis scale configurator is applied to multiple major ticks on the axis. Therefore each style in the axis has a property called PartId, which allows you to assign a value that can later be retrieved from the hit test result object. The following code snippet shows how to use this property to distinguish between different scale elements:

C#	Copy Code
NLinearScaleConfigurator linearScale = (NLinearScaleConfigurator)chart.Axis(StandardAxis.PrimaryY).ScaleConfigurator; linearScale.Title.Text = "Y Axis Title"; linearScale.Title.PartId = 1; // later in hit test NHitTestResult result = nChartControl1.HitTest(new Point(e.X, e.Y)); if (result.ChartElement == ChartElement.Axis) { if (result.AxisScalePartId == 1) { // this is an axis title } else { // this is some other axis part } }

Copy Code

NLinearScaleConfigurator linearScale = (NLinearScaleConfigurator)chart.Axis(StandardAxis.PrimaryY).ScaleConfigurator;

linearScale.Title.Text = "Y Axis Title";
linearScale.Title.PartId = 1;

// later in hit test

NHitTestResult result = nChartControl1.HitTest(new Point(e.X, e.Y));

if (result.ChartElement == ChartElement.Axis)
{
if (result.AxisScalePartId == 1)
{
// this is an axis title
}
else
{
// this is some other axis part
}
}

Visual Basic	Copy Code
Dim linearScale = CType(chart.Axis(StandardAxis.PrimaryY).ScaleConfigurator, NLinearScaleConfigurator) linearScale.Title.Text = "Y Axis Title" linearScale.Title.PartId = 1 ' later in hit test Dim result As NHitTestResult = NChartControl1.HitTest(New Point(e.X, e.Y)) If result.ChartElement = ChartElement.Axis Then If result.AxisScalePartId = 1 Then ' this is an axis title Else ' this is some other axis part End If End If

Visual Basic

Copy Code

Dim linearScale = CType(chart.Axis(StandardAxis.PrimaryY).ScaleConfigurator, NLinearScaleConfigurator)

linearScale.Title.Text = "Y Axis Title"
linearScale.Title.PartId = 1

' later in hit test

Dim result As NHitTestResult = NChartControl1.HitTest(New Point(e.X, e.Y))

If result.ChartElement = ChartElement.Axis Then
If result.AxisScalePartId = 1 Then
' this is an axis title
Else
' this is some other axis part
End If
End If

Note that the code first assigns some value to the PartId and uses this value to distringuish this part in the axis.

Related Examples

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