Question

This is a rather general question on what actually happens when an app returns from background. I have a user telling me that on opening my app that he has not used for over a day, he will still be shown the same view that he had before he closed the app (by “closed” I mean he just hit the home button to send it to background, NOT hold and then tap the cross button to kill the app completely).

I was on the impression that if an app is restored from the background after a long time, it will be reloaded completely (showing splash screen and everything), as in the cases when I opened facebook or gmail app after I haven’t used it for some time.

So my question is, do I have to implement a check somewhere on the period of time passed since my app was sent to background and reset everything when it goes over a certain threshold, or is that supposed to be handled by iOS itself… and of course if a user sent my app to the background and return after 2 minutes I would not want to refresh

Answer 1

You might have to handle that in your appdelegate methods by setting a timestamp. Since multitasking is enabled in iPhones, it will start from the same screen again. An app can be in background for a long time until user decides to kill the app.

Some of the delegate methods are

- (void)applicationWillResignActive:(UIApplication *)iApplication;
- (void)applicationDidEnterBackground:(UIApplication *)iApplication;
- (void)applicationWillEnterForeground:(UIApplication *)iApplication;
- (void)applicationDidBecomeActive:(UIApplication *)iApplication;

If you want to disable multitasking you can do that by setting a UIApplicationExistsOnSuspend key in application plist. But that will make the app quit immediately when user presses home button.