iPhone / iPad：何时在设备旋转时更改背景

Question

At what point in the rotation of a device should I replace the image that forms the background. There are 2 images, one for Landscape, one for Portrait.

Currently I use the WillRotate event, but it's 'choppy' in performance and I get warnings about not to do this in a two stage rotation.

Answer 1

I use either -

1. -(void) willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration

Sent to the view controller before performing a one-step user interface rotation.

or

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation

Sent to the view controller after the user interface rotates.