Gets the size of the cache before the viewport when the VirtualizingPanel is virtualizing.
Assembly: PresentationFramework (in PresentationFramework.dll)
In this context, "virtualize" refers to a technique by which a subset of user interface (UI) elements are generated from a larger number of data items based on which items are visible on the screen. Use a cache to avoid generating UI elements as they’re scrolled into view.
Available since 4.5