How to check if your iOS App comes into the foreground or background
I’ve been battling with those AppDelegate methods for a while, thinking “I wish there was a way that I don’t have to use those methods”. And guess what: there is!
Instead of adding code where it doesn’t make sense, we can listen to a system wide notification that tells us our app has come into the foreground, like so:
// observer checks if we're back from the background [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(myMethod) name:UIApplicationWillEnterForegroundNotification object:nil];
Here the selector “myMethod” is called when our app is about to enter the foreground. Some of the interesting notifications are
Find many more in Apple’s UIApplication Class Reference: