With a Canvas, the order of your tags is important. In the previous example,
the rectangle is superimposed on the ellipse because the ellipse appears
first in the list, and so is drawn first. If this isn’t what you
want, you can rearrange the markup or use the Canvas.ZIndex attached
property to move an element to a specific layer.

Remember, a Canvas doesn’t need to occupy an entire page. For example,
there’s no reason that you can’t create a Grid that uses a Canvas in one of its
cells. This gives you the perfect way to lock down fixed bits of drawing
logic in a dynamic, free-flowing user interface.