Cocoa: What's the difference between the frame and the bounds?

Question

UIView and its subclasses all have the properties frame and bounds. What\'s the difference?

Answer 1

frame is the origin (top left corner) and size of the view in its super view's coordinate system , this means that you translate the view in its super view by changing the frame origin , bounds on the other hand is the size and origin in its own coordinate system , so by default the bounds origin is (0,0).

most of the time the frame and bounds are congruent , but if you have a view of frame ((140,65),(200,250)) and bounds ((0,0),(200,250))for example and the view was tilted so that it stands on its bottom right corner , then the bounds will still be ((0,0),(200,250)) , but the frame is not .

the frame will be the smallest rectangle that encapsulates/surrounds the view , so the frame (as in the photo) will be ((140,65),(320,320)).

another difference is for example if you have a superView whose bounds is ((0,0),(200,200)) and this superView has a subView whose frame is ((20,20),(100,100)) and you changed the superView bounds to ((20,20),(200,200)) , then the subView frame will be still ((20,20),(100,100)) but offseted by (20,20) because its superview coordinate system was offseted by (20,20).

i hope this helps somebody.