[OC] UITabBarController

1. New CocoaTouch class -> Select Objective C -> named RootViewController

2. Disable APC error.

3. Open AppDelegate.m file and edit as below.

#import "AppDelegate.h"
#import "RootViewController.h"

@interface AppDelegate ()

@end

@implementation AppDelegate

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

    // Override point for customization after application launch.
    RootViewController *rootVC = [[RootViewController alloc] init];
    UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController: rootVC];
    [rootVC release];

    navController.title = @"ShouYe";
    UIViewController *vc1 = [[UIViewController alloc] init];
    vc1.title = @"ShouCang";
    UIViewController *vc2 = [[UIViewController alloc] init];
    vc2.title = @"SouSuo";
    UIViewController *vc3 = [[UIViewController alloc] init];
    vc3.title = @"Wo";

    NSArray *controllers = [NSArray arrayWithObjects:navController, vc1, vc2, vc3, nil];

    [navController release];
    [vc1 release];
    [vc2 release];
    [vc3 release];

    UITabBarController *tabBarController = [[UITabBarController alloc] init];
    tabBarController.viewControllers = controllers;

    self.window.rootViewController = tabBarController;
    [tabBarController release];

    return YES;
}