Getting the true visual bounding box of a WPF element?

Question

For a simplified version of my problem, I would like to calculate the bounding box of a layout-transformed (possibly even render-transformed) shape, so that I can always fit

Answer 1

The problem is not easy, as a control may draw outside its bounds.

But if you assume this doesn't happen you can solve the problem by using parent.TranslatePoint(point_in_child_coord_system, child) to transform (0,0), (child.ActualWidth,0), (child.ActualWidth, child.ActualHeight) and (0,child.ActualHeight) to the parent coord system. Then sort the x and y coordinates of all points and use minimum and maximum values to find the bounding box.

Note: sorting is necessary because of possible child rotation.