Question

I want to store an array with NSUserDefault, then, I put in applicationDidEnterBackground

[[NSUserDefaults standardUserDefaults] setObject:myArray forKey:@"myArray"];

and in application didFinishLaunchingWithOption

myArray= [[NSMutableArray alloc] 
          initWithArray:[[NSUserDefaults standardUserDefaults] 
           objectForKey:@"myArray"]];

it’s ok for multitasking device, but for not-multitasking device, how can I solve?

Answer 1

Store the object in NSUserDefaults in -applicationWillTerminate:, if it hasn’t already been saved by the invocation of -applicationDidEnterBackground: (i.e. check if multitasking is supported, if it is, then don’t save it because it’s already been saved.)

- (void) applicationWillTerminate:(UIApplication *) app {
    if([[UIDevice currentDevice] respondsToSelector:@selector(isMultitaskingSupported)] &&
       ![[UIDevice currentDevice] isMultitaskingSupported]) {
       [[NSUserDefaults standardUserDefaults] setObject:myArray forKey:@"myArray"];
    }
}