When are each of these iOS backgrounding delegate methods called?

Question

I am confused which of these iOS delegate methods are called in which situations:

- (void)applicationWillResignActive:(UIApplication *)application {
}


- (void)applicationDidEnterBackground:(UIApplication *)application {
}


- (void)applicationWillEnterForeground:(UIApplication *)application {
}


- (void)applicationDidBecomeActive:(UIApplication *)application {
}


- (void)applicationWillTerminate:(UIApplication *)application {
    }

I've tried messing around with them because I want my app to do some actions right before it exits if the home button was pressed and also once when the app re-opens. Could anyone give me a quick summary of when to use each one of these/when they are called in my app?

Answer 1

- (void)applicationWillResignActive:(UIApplication *)application {
// Home button was pressed! Do some actions here!
}


- (void)applicationDidEnterBackground:(UIApplication *)application {
// Your app is now running in the background. It is no longer visible.
}


- (void)applicationWillEnterForeground:(UIApplication *)application {
// Your application was running in the background, but is now being re-opened
}


- (void)applicationDidBecomeActive:(UIApplication *)application {
// You application is now once again active
}


- (void)applicationWillTerminate:(UIApplication *)application {
// Your application is about to QUIT.
    }