iOS TabBarController 问题

Question

TabBar将是关于2个问题。我使用 TabBar 和 NavigationController 的组合。如以下链接。

http://developer.apple.com/library/ios/ #featuredarticles/ViewControllerPGforiPhoneOS/CombiningViewControllers/CombiningViewControllers.html

问题 1：

我想出现在另一个 ViewController 的 TabBar 之前。这里要做几项检查。 （例如，Facebook 登录）如果满足先决条件，选项卡栏将可见。我该怎么办？

问题2：

TabBar 屏幕图标出现在第一个TabBar 的中间。下面的代码顺序也会影响TabBarItem的顺序。

self.tabBarController.viewControllers = [NSArray arrayWithObjects: viewController1, viewController2, nil];

谢谢。

奥坎·沙辛

Answer 1

对于那些有同样问题的人：

我正在使用 Xcode 4.2。我创建了选项卡式应用程序。

答案 1：

对于加载屏幕，

我创建了一个新的 ViewController。

AppDelegate.m

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

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

    UIViewController *viewControllerLoading = [[LoadingViewController alloc] initWithNibName:@"LoadingViewController" bundle:nil];

    self.window.rootViewController = viewControllerLoading;

    [self.window makeKeyAndVisible];

    return YES;
}

LoadingViewController.h

@interface LoadingViewController : UIViewController <UITabBarControllerDelegate>

@property (strong, nonatomic) UITabBarController *tabBarController;

@end

LoadingViewController.m

 UIViewController *viewControllerFriends = [[FriendsViewController alloc] initWithNibName:@"FriendsViewController" bundle:nil];
    UINavigationController* navController1 = [[UINavigationController alloc]
                                              initWithRootViewController:viewControllerFriends];
    UIViewController *viewConrollerMessages = [[MessagesViewController alloc] initWithNibName:@"MessagesViewController" bundle:nil];
    UINavigationController* navController2 = [[UINavigationController alloc]
                                              initWithRootViewController:viewConrollerMessages];
    UIViewController *viewControllerWorld = [[WorldViewController alloc] initWithNibName:@"WorldViewController" bundle:nil];
    UINavigationController* navController3 = [[UINavigationController alloc]
                                              initWithRootViewController:viewControllerWorld];

    UIViewController *viewControllerCheckIn = [[CheckInViewController alloc] initWithNibName:@"CheckinViewController" bundle:nil];
    UINavigationController* navController4 = [[UINavigationController alloc]
                                              initWithRootViewController:viewControllerCheckIn];

    UIViewController *viewControllerProfile = [[ProfileViewController alloc] initWithNibName:@"ProfileViewController" bundle:nil];
    UINavigationController* navController5 = [[UINavigationController alloc]
                                              initWithRootViewController:viewControllerProfile];

    self.tabBarController = [[UITabBarController alloc] init];
    self.tabBarController.viewControllers = [NSArray arrayWithObjects:navController1, navController2, navController3, navController4, navController5, nil];

    [self.view addSubview:self.tabBarController.view];

答案 2：

    self.tabBarController.selectedIndex = 2;

最诚挚的问候

Okan Sahin