In Development
Last Updated: 31 Aug 2026 11:26 by ADMIN
Craig
Created on: 05 Aug 2026 14:08
Category: Chart
Type: Bug Report
4
Chart: [WinUI] ChartTrackBallBehavior throws ArgumentNullException when pointer enters chart with no series
When pointer enters chart with no data and series and having a trackball behavior added, argument null exception occurs.
2 comments
ADMIN
Didi
Posted on: 31 Aug 2026 11:26

Hello Craig,

A follow up message will be sent to the support ticket. Thank you for your feedback.

Regards,
Didi
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Craig
Posted on: 28 Aug 2026 15:43
After adding the delay as suggested we followed to avoid the occurrence of this error. 
But, We still see the crash issue. This crashes the app. 
Could we make sure this is fixed at earliest as this is happening at prod. 



            // Re-apply tooltip suppression after every render because Chart.Series.Clear()
            // discards the old native series objects and the empty template must be re-stamped
            // onto each newly created native series instance.
#if WINDOWS
            SuppressNativeTrackballTooltip();

            // Defer trackball reattachment with enough delay for ArrangeOverride to complete.
            // A single Dispatcher.Dispatch (one frame) is insufficient — Telerik's
            // ArrangeOverride → CallUpdateUI → UpdateVisuals → UpdateIntersectionPoints
            // fires on the same or next frame with stale ChartDataContext.
            // 200ms guarantees the layout cycle has fully completed and native series
            // data points are initialized before the trackball can query them.
            Dispatcher.DispatchDelayed(TimeSpan.FromMilliseconds(200), SafeReattachTrackball);
#endif