Catching vertical manipulation

[Jon]

Hi.
I'm trying to execute som code in a ManipulationDelta event handler, but it never fires. I've added the method to the ManipulationDelta event of the JumpList and set the UseOptimizedManipulationRouting to false, but it doesn't fire. I've also tried to make a custom class inheriting from the JumpList and overriding the OnManipulationDelta method there, but no luck.

Is there any way to catch the vertical manipulation? The horizontal delta is caught just fine.

Thanks.

[Deyan]

Hi Jon,

Thanks for writing and for your question.



Unfortunately using these events in the context of a ScrollViewer based control is a tricky thing. As you may already know, with the introduction of Windows Phone 7.5 (Mango) Microsoft have optimized the scrolling experience by creating a new Manipulation thread where the input first goes for handling and is forwarded to you in given time intervals, not constantly.



This is explained here in a good manner:



http://blogs.msdn.com/b/slmperf/archive/2011/06/02/listbox-scrollviewer-performance-improvement-for-mango-and-how-it-impacts-your-existing-application.aspx



So, you can either turn this entirely off and have the glitchy scrolling, or have the optimized scrolling and do not rely on the deterministic behavior of the manipulation events.



Regards,

Deyan
Telerik