How can I show the the tooltip (chart value) on a touchscreen, in the chart?
From my understanding the XamDataChart doesn't support Touch Gestures. You could invert the touch events to mouse events, as explained in the following post:
Is it possible when I click (touch) on the chart serie, the tooltip appears?
Which series are you using?
In our touch based application I am using the following series: column, range column, line and area series. Currently the user are not able to see the series values (tooltip), when working on touch screens.
If you press long enough Windows should cause the tooltips to display if the series already enabled tooltips, however it's longer than a couple seconds.
By default, the chart pans and zooms when touching which we've caused the tooltips to suppressed. This is one reason why we don't show tooltips initially when you touch the chart. You'll need to opt in to show tooltips with touches.
To enable touch-based tooltips you can either opt in to our default tooltips or use our Item/CategoryTooltipLayer.
For option 1, first you must access the Series and enable the property ShowDefaultTooltips to True, Next, enable IsDragCrosshairEnabled (exposed on the chart itself that will show the crosshair at the touch point) and show the tooltip. If you don't want a crosshair then you will have to remove the built in CrosshairLineStyle which is generating the crosshair lines.
For option 2, please visit our online documentation at: item or category tooltip layer for more details.
Let me know if you have any questions.