Regarding transitionFromView:toView:duration:options:completion: Apple doc says this in last few lines:
This method modifies the views in their view h
The statement "it is your responsibility to update the view controller appropriately to handle the change." it meant that you have to appropriately call view hierarchy delegate methods such as:
- (void)viewDidLoad;
- (void)viewDidUnload;
- (void)viewWillAppear;
- (void)viewDidDisappear;
And other methods that are responsible for proper view management.
Here are some examples.