NavigationBar

 //基本不用
//    NSShadow *shadow = [[NSShadow alloc] init];
//    shadow.shadowColor = [UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:1.0];  // 阴影颜色
//    shadow.shadowOffset = CGSizeMake(0, 2);  // 阴影偏移量
    
    //设置背景颜色、文字属性
    NSDictionary *titleTextAttributes = @{NSForegroundColorAttributeName : [UIColor whiteColor],
                                          NSFontAttributeName : [UIFont systemFontOfSize:18 weight:UIFontWeightMedium],};
    //                                              NSShadowAttributeName:shadow};
    
    if (@available(iOS 13.0, *)) {
        UINavigationBarAppearance *appearance = [[UINavigationBarAppearance alloc] init];
        appearance.backgroundEffect = nil;
        appearance.backgroundColor = [UIColor redColor];
        appearance.backgroundImage = image;
        appearance.titleTextAttributes = titleTextAttributes;
        // 将设置应用到导航栏的 standardAppearance 和 scrollEdgeAppearance
        self.navigationController.navigationBar.standardAppearance = appearance;
        self.navigationController.navigationBar.scrollEdgeAppearance = appearance;
    } else {
        self.navigationController.navigationBar.barTintColor = [UIColor redColor];
        [self.navigationController.navigationBar setTitleTextAttributes:titleTextAttributes];
        //阴影线
        self.navigationController.navigationBar.shadowImage = [UIImage new];
        // 透明
        self.navigationController.navigationBar.translucent = NO;
        // 背景图片
        [self.navigationController.navigationBar setBackgroundImage:image forBarMetrics:UIBarMetricsDefault];
        //背景颜色
        self.navigationController.navigationBar.backgroundColor = [UIColor redColor];
    }
    
    // 创建返回按钮
    UIBarButtonItem *backBtn = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];
    self.navigationItem.backBarButtonItem = backBtn;

TabBar

if (@available(iOS 13.0, *)) {
        UITabBarAppearance *tabbarAppearnce = [[UITabBarAppearance alloc]init];
        UITabBarItemAppearance *itemAppearance =  [[UITabBarItemAppearance alloc] initWithStyle:(UITabBarItemAppearanceStyleStacked)];
        itemAppearance.normal.titleTextAttributes = @{NSForegroundColorAttributeName:[UIColor purpleColor]};
        itemAppearance.selected.titleTextAttributes = @{NSForegroundColorAttributeName:[UIColor redColor]};
//        itemAppearance.normal.iconColor = [UIColor blueColor];
//        itemAppearance.selected.iconColor = [UIColor redColor];
//        itemAppearance.normal.badgeBackgroundColor = [UIColor yellowColor];
//        itemAppearance.selected.badgeBackgroundColor = [UIColor yellowColor];
//        itemAppearance.normal.badgeTextAttributes = @{NSForegroundColorAttributeName:[UIColor redColor]};
        tabbarAppearnce.stackedLayoutAppearance = itemAppearance;
        tabbarAppearnce.backgroundColor = [UIColor orangeColor];
        tabbarAppearnce.backgroundEffect = nil;
        self.tabBar.standardAppearance = tabbarAppearnce;
        if (@available(iOS 15.0, *)) {
            self.tabBar.scrollEdgeAppearance = tabbarAppearnce;
        }
    }else{
        //背景颜色
        self.tabBar.backgroundColor = [UIColor orangeColor];
        //选中颜色
        self.tabBar.tintColor = [UIColor redColor];
        //没有选中的颜色
        self.tabBar.unselectedItemTintColor = [UIColor whiteColor];
        //去掉黑线
        self.tabBar.shadowImage = [UIImage new];
        
    }