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

    // 1. 创建窗口

    self.window = [[UIWindow alloc] init];

    self.window.frame = [UIScreen mainScreen].bounds;

    // 2. 设置根控制器

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

    self.window.rootViewController = tabbarVc;

    // 3. 设置子控制器属性

    DJHomeViewController *homeVc = [[DJHomeViewController alloc] init];

    [self setChildVc:homeVc withTitle:@"首页" image:@"tabbar_home" selectedImage:@"tabbar_home_selected"];

    DJMessageCenterViewController *messageCenterVc = [[DJMessageCenterViewController alloc] init];

    [self setChildVc:messageCenterVc withTitle:@"消息" image:@"tabbar_message_center" selectedImage:@"tabbar_message_center_selected"];

    DJDiscoverViewController *discoverVc = [[DJDiscoverViewController alloc] init];

    [self setChildVc:discoverVc withTitle:@"发现" image:@"tabbar_discover" selectedImage:@"tabbar_discover_selected"];

    DJProfileViewController *profileVc = [[DJProfileViewController alloc] init];

    [self setChildVc:profileVc withTitle:@"我" image:@"tabbar_profile" selectedImage:@"tabbar_profile_selected"];

    // 4. 添加子控制器

    [tabbarVc addChildViewController:homeVc];

    [tabbarVc addChildViewController:messageCenterVc];

    [tabbarVc addChildViewController:discoverVc];

    [tabbarVc addChildViewController:profileVc];

    // 5. 显示窗口

    [self.window makeKeyAndVisible];

    return YES;

}

- (void)setChildVc:(UIViewController *)vc withTitle:(NSString *)title image:(NSString *)image selectedImage:(NSString *)selectedImage {

    vc.view.backgroundColor = DJRandomColor;

    vc.tabBarItem.title = title;

    // 设置tabbarItem 选中图片

    vc.tabBarItem.image = [UIImage imageNamed:image];

    vc.tabBarItem.selectedImage = [[UIImage imageNamed:selectedImage] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];

    // 设置tabarItem 选中颜色

    NSMutableDictionary *textAttrs = [NSMutableDictionary dictionary];

    textAttrs[NSForegroundColorAttributeName] = DJColor(, , );

    NSMutableDictionary *selectedTextAttrs = [NSMutableDictionary dictionary];

    selectedTextAttrs[NSForegroundColorAttributeName] = [UIColor orangeColor];

    [vc.tabBarItem setTitleTextAttributes:textAttrs forState:UIControlStateNormal];

    [vc.tabBarItem setTitleTextAttributes:selectedTextAttrs forState:UIControlStateSelected];

}