creating a background task in iOS 4

creating a background task in iOS 4

- (void)applicationDidFinishLaunching:(UIApplication *)app {
    if ([UIDevice currentDevice].multitaskingSupported) {
        UIBackgroundTaskIdentifier *backgroundTask = 
        [app beginBackgroundTaskWithExpirationHandler:^{
            /* just fail if this happens. */
            NSLog(@"BackgroundTask Expiration Handler is called");
            [app endBackgroundTask:backgroundTask];
        }];
    }
}