UITabBarController基礎篇

       屬性

       viewControllers：視圖控制器字典

       selectedViewController：當前正在顯示的VC

       selectedIndex:預設選中VC指數

       moreNavigationController:更多導覽列 (超過五個vc出現)

       customizableViewControllers：更多視圖中可編輯的視圖

       tabBar：標籤欄

       方法

       - (void)setViewControllers:(NSArray<__kindof UIViewController *> * __nullable)viewControllers animated:(BOOL)animated；管理檢視控制器

       代理方法

        - (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController；設定標籤欄中的某個選項能否被選中

        - (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController;標籤欄的某個標籤被選中後執行的操作

        - (void)tabBarController:(UITabBarController *)tabBarController willBeginCustomizingViewControllers:(NSArray<__kindof UIViewController *> *)viewControllers ;在標籤欄中更多視圖控制器中的視圖開始編輯執行的方法
        - (void)tabBarController:(UITabBarController *)tabBarController willEndCustomizingViewControllers:(NSArray<__kindof UIViewController *> *)viewControllers changed:(BOOL)changed;在標籤欄中更多視圖控制器中的視圖將要結束編輯執行的方法
        - (void)tabBarController:(UITabBarController *)tabBarController didEndCustomizingViewControllers:(NSArray<__kindof UIViewController *> *)viewControllers changed:(BOOL)changed；在標籤欄中更多視圖控制器中的視圖結束編輯執行的方法

        - (UIInterfaceOrientationMask)tabBarControllerSupportedInterfaceOrientations:(UITabBarController *)tabBarController

        - (UIInterfaceOrientation)tabBarControllerPreferredInterfaceOrientationForPresentation:(UITabBarController *)tabBarController

        - (nullable id <UIViewControllerInteractiveTransitioning>)tabBarController:(UITabBarController *)tabBarController
                      interactionControllerForAnimationController: (id <UIViewControllerAnimatedTransitioning>)animationController

        - (nullable id <UIViewControllerAnimatedTransitioning>)tabBarController:(UITabBarController *)tabBarController
            animationControllerForTransitionFromViewController:(UIViewController *)fromVC
                                              toViewController:(UIViewController *)toVC