I implement some additional logic for elements arrangement.
I override MeasureOverride and ArrangeOverride. If I inherit from StackPanel everything works. What is not the case for VirtualizingStackPanel as a parent. Debug revealed that InternalChildren.Count returns zero as if no element's container has been generated yet. I definitely miss something for VSP. And I guess it is virtualizing. Can anyone help me with this?
P.S. Both variants of inheritance were tested for the ItemsControl.ItemsPanel
