IOS学习笔记UITabBarController使用教程

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    
    
    
    UILabel *lab = [[UILabel alloc]initWithFrame:CGRectMake(320/2-140/2, 80, 140, 40)];
    lab.text = @"王振";
    lab.textAlignment = UITextAlignmentCenter;
    lab.backgroundColor = [UIColor blueColor];
    [self.window addSubview:lab];
    
    //your code
    UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(320/2-140/2,480/2-40/2, 140, 40)];
    label.text = @"Hello World";
    label.backgroundColor = [UIColor cyanColor];
    label.textAlignment = UITextAlignmentCenter;
    [self.window addSubview:label];
    
    HomeViewController *view1 = [[HomeViewController alloc]init];
    UINavigationController *v1 = [[UINavigationController alloc]initWithRootViewController:view1];
 
    
    MessageViewController *view2 = [[MessageViewController alloc]init];
    UINavigationController *v2 = [[UINavigationController alloc]initWithRootViewController:view2];
    
    SearchViewController *view3 = [[SearchViewController alloc]init];
    UINavigationController *v3 = [[UINavigationController alloc]initWithRootViewController:view3];
    
    SettingViewController *view4 = [[SettingViewController alloc]init];
    UINavigationController *v4 = [[UINavigationController alloc]initWithRootViewController:view4];
    
    
    //NSArray *arr = @[view1,view2,view3,view4];
    
    NSArray *viewControllers = [NSArray arrayWithObjects:v1,v2,v3,v4 , nil];
 
    
    UITabBarController *mainViewController = [[UITabBarController alloc]init];
    mainViewController.viewControllers = viewControllers;
    //[mainViewController setViewControllers:mainViewController];
    
    //[mainViewController release];
    [UIApplication sharedApplication].applicationIconBadgeNumber = 2;
    
    [self.window setRootViewController:mainViewController];
    
    
    return YES;
}