基于代码的 UITabbarController与UINavgationController 实现下导航页面切换

- (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];

//初始化一个 UITabBarController

UITabBarController *tabbarController=[[UITabBarController alloc]init];

//初始化  UINavigationController，并把UIViewController 设为rootview
ZAFirstViewController *firstVC=[[ZAFirstViewController alloc]init];
firstVC.title=@"1";
UINavigationController *firstNV=[[UINavigationController alloc]initWithRootViewController:firstVC];

ZASecondViewController *secondVC=[[ZASecondViewController alloc]init];
secondVC.title=@"2";
UINavigationController *secondNV=[[UINavigationController alloc]initWithRootViewController:secondVC];

ZAThirdViewController *thirdVC=[[ZAThirdViewController alloc]init];
thirdVC.title=@"2";
UINavigationController *thirdNV=[[UINavigationController alloc]initWithRootViewController:thirdVC];

//设置UITabBarController的viewControllers数组为  UINavigationController 数组
tabbarController.viewControllers=@[firstNV,secondNV,thirdNV];

//将window的rootViewController 设置为 UITabBarController
self.window.rootViewController=tabbarController;

[self.window makeKeyAndVisible];
return YES;
}