Saving and Restoring Application State on iOS 6 without Storyboards

Question

I have done test app following this tutorial

I try to do the same without using Storyboards and it isn't work. I have enabled state preservation and restoration in AppDelegate. I have assigned restorationIdentifier to all my controllers and their views. I think i have to implement some additional code in AppDelegate to restore rootviewcontroller, but i cannot find the right way to do this.

-(BOOL)application:(UIApplication *)application shouldRestoreApplicationState:(NSCoder *)coder
{
    return YES;
}

-(BOOL)application:(UIApplication *)application shouldSaveApplicationState:(NSCoder *)coder
{
    return YES;
}


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    // Override point for customization after application launch.
    UIViewController *viewController1 = [[[StateTestFirstViewController alloc] initWithNibName:@"StateTestFirstViewController" bundle:nil] autorelease];
    UIViewController *viewController2 = [[[StateTestSecondViewController alloc] initWithNibName:@"StateTestSecondViewController" bundle:nil] autorelease];
    self.tabBarController = [[[UITabBarController alloc] init] autorelease];
    self.tabBarController.restorationIdentifier = @"TabBarController";
    self.tabBarController.viewControllers = @[viewController1, viewController2];
    self.window.rootViewController = self.tabBarController;

    [self.window makeKeyAndVisible];

    return YES;
}

Answer 1

Actually, your view controllers are restored between application:willFinishLaunchingWithOptions: and application:didFinishLaunchingWithOptions: so if you change your code to:

- (BOOL)application:(UIApplication *)application willFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];

    UIViewController *viewController1 = [[[StateTestFirstViewController alloc] initWithNibName:@"StateTestFirstViewController" bundle:nil] autorelease];
    UIViewController *viewController2 = [[[StateTestSecondViewController alloc] initWithNibName:@"StateTestSecondViewController" bundle:nil] autorelease];
    self.tabBarController = [[[UITabBarController alloc] init] autorelease];
    self.tabBarController.restorationIdentifier = @"TabBarController";
    self.tabBarController.viewControllers = @[viewController1, viewController2];
    self.window.rootViewController = self.tabBarController;
    return YES;
}

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {                
    [self.window makeKeyAndVisible];

    return YES;
}

It worked for me. Also I recommend that you watch the WWDC 2012 Session 208 — Saving and Restoring Application State on iOS.