This sample depicts the crosshair behavior in the charts. To view the crosshair and its tooltip, hover over the chart or tap on it in touch-enabled devices.
The crosshair is used to inspect or focus on an individual data point using a vertical and a horizontal line. You can enable the crosshair using the Enable property in the ChartCrosshairSettings class and customize its tooltip by using the ChartAxisCrosshairTooltip in the axis.
More information about the crosshair can be found in this documentation section.