What exactly is the relationship between a Surface and Canvas.
Please explain.
A surface is a buffer. A Canvas holds the drawing.
Views are not attached to the Canvas nor the Surface. The window is tied to a Surface and the ViewRoot asks the Surface for a Canvas that is then used by the Views to draw onto.
For a detailled anwser, you can read this whole discussion, really interesting.
来源：https://stackoverflow.com/questions/3370212/relationship-between-surface-and-canvas-android