How to use SelectionChangedCommand

I trying to get data from CollectionView to ViewModel when activeItem has changed.
I try to bind ICommand on SelectionChangedCommand="{Binding Swipe}" but on swipe I don't get data from CollectionView. Command "Swipe" is not triggered. I am doing something wrong, but can't find appropriate sample on documentation.
So my question is: How to use SelectionChangedCommand ? Or How to track active item from CollectionView in my ViewModel .
My code is on github: https://github.com/Darkoshacy/CollectionViewMySample