NSUserDefaults not working on iPhone 4.0 device?

Question

Hello all

i am using NSUserDefaults to save data from the app and when the user leaves the app and then come back to it all the values are restored.

the thing is that it does save the values while the app is running in background mode. but when i close the app from multitasking and re-open it the app comes back as new with no values saved. i have added the methods beginInBackground and applicationWillterminate but no help is their a new way of doing this on the new 4.0?

PS. i am testing on the device only. i could not use the simulator because i am using Map kit.

Answer 1

Are you calling the synchronize method?

Answer 2

In your applicationDidEnterBackground just use the following code:

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults synchronize];

Answer 3

The problem you are having is that you are expecting an NSApplicationWillTerminateNotification that is not getting sent in 4.0 because NSApplicationDidEnterBackgroundNotification is getting sent instead. I have had the same problem. Register both notifications for your storage function and it will work again. You don't need conditional code since even if you register for a notification that does not exist in 3.0, it will never get called there so there will be no crash.

If you are not using notifications you can also override applicationDidEnterBackground: as noted in the above comment.