WPF Canvas inheritance, mouse events not detected

I made a child class of Canvas WPF class to change rendering function. However, when I try to change its background property in child class to handle mouse events properly it is no开发者_运维百科t working. When manually set background in xaml with Background="White" in editor it is not working.

Where am I wrong. Beside that I would prefer adding canvaschild dynamically instead of using editor.

Thanks