切換根視圖控制器

Question

我已經有一個帶有UINavigationController的應用程序，但是我想切換到UITabBarController，問題是當我從一開始切換到UItab時它不起作用，所以我在委托方法中切換了它，但是它也不起作用！ 應用程序委托中的所有代碼 。

self.navigationController = [[UINavigationController alloc] initWithRootViewController:[[UIViewController alloc] init]];
    self.tabBarController = [[UITabBarController alloc] init];


    if ([PFUser currentUser]) {
        // Present wall straight-away
        [self presentWallViewControllerAnimated:NO];
    } else {
        // Go to the welcome screen and have them log in or create an account.
        [self presentLoginViewController];
    }

    [PFAnalytics trackAppOpenedWithLaunchOptions:launchOptions];

    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.rootViewController = self.navigationController;
    [self.window makeKeyAndVisible];

我想打開它的委托方法：

- (void)presentWallViewControllerAnimated:(BOOL)animated {
    NSLog(@"Called:presentWallViewControllerAnimated ");
//    self.navigationController = nil;

    self.tabBarController = [[UITabBarController alloc] init];

    PAWWallViewController *wallViewController = [[PAWWallViewController alloc] initWithNibName:nil bundle:nil];
    wallViewController.delegate = self;


    // Set up the first View Controller
    UIViewController *vc1 = [[UIViewController alloc] init];
    vc1.view.backgroundColor = [UIColor orangeColor];
    vc1.tabBarItem.title = @"Orange";
    vc1.tabBarItem.image = [UIImage imageNamed:@"heart"];

    // Set up the second View Controller
    UIViewController *vc2 = [[UIViewController alloc] init];
    vc2.view.backgroundColor = [UIColor purpleColor];
    vc2.tabBarItem.title = @"Purple";
    vc2.tabBarItem.image = [UIImage imageNamed:@"star"];

    // Set up the Tab Bar Controller to have two tabs

    [self.tabBarController setViewControllers:@[ vc1, vc2]];

    self.window.rootViewController = self.tabBarController;

    [self.window makeKeyAndVisible];



//    [self.window addSubview:tabBarController.view];
//    [self.navigationController setViewControllers:@[ tabBarController ] animated:animated];
}

Answer 1

記住要處理視圖轉換：

UIViewController *vc = // any vc that's initialized properly    
window.rootViewController = vc;

[UIView transitionWithView:window
                  duration:0.3  // 0.0 for immediate
                   options:UIViewAnimationOptionTransitionCrossDissolve // several enums to choose from here
                animations:nil
                completion:nil];

而且您在第一次之后就不需要makeKeyAndVisible了。

Answer 2

您調用了- (void)presentWallViewControllerAnimated:(BOOL)animated但在您調用的didFinishLaunchingWithOptions結尾時

self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.rootViewController = self.navigationController;
[self.window makeKeyAndVisible];

因此，標簽欄將永遠無法工作！