在没有故事板的iOS 6上保存和恢复应用程序状态

Question

我按照本教程完成了测试应用程序

我尝试在不使用Storyboard的情况下做同样的事情,但这不起作用.我在AppDelegate中启用了状态保存和恢复.我已经为我的所有控制器及其视图分配了restorationIdentifier.我想我必须在AppDelegate中实现一些额外的代码来恢复rootviewcontroller,但我找不到正确的方法来做到这一点.

-(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

实际上,您的视图控制器会在两者之间进行恢复application:willFinishLaunchingWithOptions:,application:didFinishLaunchingWithOptions:因此如果您将代码更改为:

- (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;
}

它对我有用.另外,我建议您观看WWDC 2012 Session 208 - 在iOS上保存和恢复应用程序状态.