导航视图（三）

#import "AppDelegate.h"
#import "Tab1ViewController.h"
#import "Tab2ViewController.h"
#import "Tab3ViewController.h"

@interface AppDelegate ()

@end

@implementation AppDelegate


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    
    
    self.window = [[UIWindow alloc]initWithFrame:[[UIScreen mainScreen]bounds]];
    
    UITabBarController *tabBarController = [[UITabBarController alloc] init];
    self.window.rootViewController = tabBarController;
    
    
    Tab1ViewController *tab1 = [[Tab1ViewController alloc]init];
    Tab2ViewController *tab2 = [[Tab2ViewController alloc]init];
    Tab3ViewController *tab3 = [[Tab3ViewController alloc]init];
    
    UINavigationController *nav1 = [[UINavigationController alloc]initWithRootViewController:tab1];
    UINavigationController *nav2 = [[UINavigationController alloc]initWithRootViewController:tab2];
    UINavigationController *nav3 = [[UINavigationController alloc]initWithRootViewController:tab3];
    
    nav1.title = @"Title1";
    nav2.title = @"Title2";
    nav3.title = @"Title3";
    
    nav1.tabBarItem.image = [UIImage imageNamed:@"btn_1_h"];
    nav2.tabBarItem.image = [UIImage imageNamed:@"btn_2_h"];
    nav3.tabBarItem.image = [UIImage imageNamed:@"btn_3_h"];
    
    
    NSArray *controllers = [NSArray arrayWithObjects: nav1, nav2, nav3, nil];
    
    tabBarController.viewControllers = controllers;
    
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    
    return YES;
}