Question

I have 2 view controllers, vc1 and vc2. A modal segue is invoked from vc1 when I want to load vc2. Say I background the app when vc2 is showing. Why isn’t viewDidAppear called when the app is re-opened to the view that was left off? How else am I able to detect every time vc2 appears?

Answer 1

You could register for the UIApplicationDidBecomeActiveNotification in VC2 and call viewDidAppear from there. Do this in your viewDidLoad of VC2:

[[NSNotificationCenter defaultCenter] addObserver:self
                     selector:@selector(somethingThatWillCallViewDidAppear:)
                       name:UIApplicationDidBecomeActiveNotification 
                                  object:nil];

As rmaddy says below, make sure to remove the observer in dealloc or viewDidUnload.