WPF: Canvas Z-Index Bug

Answer 1

In wpf, technically your mouse IS over 18. The way the events (may) be triggered is as follows:

I'm over "16", call the mouseover for 16 I'm over "18", call the mouseover for 18

Since 18 was the most recently called, it's selected (again, just my guess).

In the event args for the mousemove event (I assume mousemove), make sure to set e.Handled = true, this way it's only processed once