Poor performance following ShadowAssist.CacheMode change #3616

Bug explanation

It seems that specifically following commit #3616 to change the default ShadowAssist CacheMode behaviour, I find the performance of our WPF app to be a lot slower and laggy than it was before, particularly when it comes to animations such as those in the DialogHost flyouts. It's particularly bad after resizing the window or in full screen.

I'm trying to figure out the best way to replicate the old behaviour. I've tried to set a CacheMode with EnableClearType and SnapsToDevicePixels but it seems like I have to set this all the way down and just setting it on the window or main containing control doesn't work.

Would appreciate any guidance on this. Has anyone else had a similar problem or know the best way to handle the CacheMode property globally? Is that even the right approach or should it only be set for troublesome controls?

Version

5.2.1

Inizia esaminando il commit #3616 e riproducendo il rallentamento nell’app WPF, concentrandoti sulle animazioni flyout di DialogHost dopo il ridimensionamento della finestra o l’ingresso a schermo intero. Confronta il comportamento di CacheMode con quello della versione precedente e determina se il problema è globale o limitato ai controlli problematici; il lavoro sarà considerato completato quando saranno disponibili una causa riproducibile e un approccio documentato per gestirla.