ios7 uitabbarcontroller

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{
    
    
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    
    [self.window makeKeyAndVisible];
    
    //创建 firstVC
    FirstViewController *firstViewController = [[FirstViewController alloc]initWithNibName:nil bundle:NULL];
    //创建first的nav，设置rootview为firstViewController
    UINavigationController *firstNavigationController =
        [[UINavigationController alloc]
         initWithRootViewController:firstViewController];
    
    //创建secondVC
    SecondViewController *secondViewController = [[SecondViewController alloc] initWithNibName:nil bundle:NULL];
    //创建second的nav，设置rootView为secondViewController
    UINavigationController *secondNavigationController = [[UINavigationController alloc] initWithRootViewController:secondViewController];
    //创建Tab
    UITabBarController *tabBarController = [[UITabBarController alloc] init];
    //添加2个view到 tab
    [tabBarController setViewControllers:
        @[firstNavigationController, secondNavigationController]];
    
    self.window.rootViewController = tabBarController;
    
    return YES;
    
}

- (id)initWithNibName:(NSString *)nibNameOrNil
               bundle:(NSBundle *)nibBundleOrNil{
    
    self = [super initWithNibName:nibNameOrNil
                           bundle:nibBundleOrNil];
    if (self != nil) {
        //nav title和bar title为First
        self.title = @"First";
        //设置tabbar图片
        self.tabBarItem.image = [UIImage imageNamed:@"FirstTab"];
    }
    return self;
    
}
- (void)viewDidLoad{
    [super viewDidLoad];
    //设置view背景色为白色
    self.view.backgroundColor = [UIColor whiteColor];
}

- (id)initWithNibName:(NSString *)nibNameOrNil
               bundle:(NSBundle *)nibBundleOrNil{
    
    self = [super initWithNibName:nibNameOrNil
                           bundle:nibBundleOrNil];
    if (self != nil) {
        //nav title和bar title为Second
        self.title = @"Second";
        //设置tabbar图片
        self.tabBarItem.image = [UIImage imageNamed:@"SecondTab"];
    }
    return self;
    
}

- (void)viewDidLoad{
    [super viewDidLoad];
    //设置view背景色为白色
    self.view.backgroundColor = [UIColor whiteColor];
}