IOS TabBarController问题

Question

TabBar大约有两个问题。我使用的是TabBar和NavigationController的组合。作为下面的链接。

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

问题1:

我想在另一个TabBar的ViewController面前出现。有几个检查要做。(例如，Facebook登录)如果满足先决条件，则选项卡将是可见的。我该怎么做？

问题2:

出现在第一个TabBar中间的TabBar屏幕图标希望它是这样的。下面的代码序列也会影响TabBarItem的顺序。

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

谢谢。

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Answer 1

对于那些有同样问题的人：

我使用的是Xcode 4.2。我创建了选项卡式应用程序。

答案1:

为了装载屏幕，

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;

诚挚的问候

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