一锦庸、在iOS13之前敬锐，我們?nèi)コ诰€是這樣設(shè)置的

[self.tabBar setBackgroundImage:[UIImage new]];
[self.tabBar setShadowImage:[UIImage new]];

二、iOS13引入了UITabBarAppearance類剩盒，所以我們?nèi)コ诰€需要這樣設(shè)置

if(@available(iOS 13.0, *)) {
   UITabBarAppearance *appearance = [UITabBarAppearance new];
   appearance.backgroundColor = [UIColor clearColor];
   appearance.backgroundImage = [UIImage new];
   appearance.shadowColor = [UIColor clearColor];
   appearance.shadowImage = [UIImage new];
   [UITabBar appearance].standardAppearance = appearance;
    }

三谷婆、給tabBar設(shè)置文字樣式，頁面跳轉(zhuǎn)返回后辽聊，在iOS13會無效纪挎，變成系統(tǒng)藍(lán)了

- (void)addChildVc:(UIViewController *)childVc title:(NSString *)title image:(NSString *)image selectedImage:(NSString *)selectedImage
{
    // 設(shè)置子控制器的文字
    childVc.title = title; // 同時(shí)設(shè)置tabbar和navigationBar的文字
    
    // 設(shè)置子控制器的圖片
    childVc.tabBarItem.image = [[UIImage imageNamed:image]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    childVc.tabBarItem.selectedImage = [[UIImage imageNamed:selectedImage]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    // 設(shè)置文字的樣式
    NSMutableDictionary *textAttrs = [NSMutableDictionary dictionary];
    textAttrs[NSForegroundColorAttributeName] = kHexColor(0x939393);
    NSMutableDictionary *selectTextAttrs = [NSMutableDictionary dictionary];
    selectTextAttrs[NSForegroundColorAttributeName] = kHexColor(0x1A1A1A);
    [childVc.tabBarItem setTitleTextAttributes:textAttrs forState:UIControlStateNormal];
    [childVc.tabBarItem setTitleTextAttributes:selectTextAttrs forState:UIControlStateSelected];

    [self addChildViewController:childVc];
}

解決：也是iOS13新加的UITabBarAppearance類有關(guān)

- (void)addChildVc:(UIViewController *)childVc title:(NSString *)title image:(NSString *)image selectedImage:(NSString *)selectedImage
{
    // 設(shè)置子控制器的文字
    childVc.title = title; // 同時(shí)設(shè)置tabbar和navigationBar的文字
    
    // 設(shè)置子控制器的圖片
    childVc.tabBarItem.image = [[UIImage imageNamed:image]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    childVc.tabBarItem.selectedImage = [[UIImage imageNamed:selectedImage]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    // 設(shè)置文字的樣式
    NSMutableDictionary *textAttrs = [NSMutableDictionary dictionary];
    textAttrs[NSForegroundColorAttributeName] = kHexColor(0x939393);
    NSMutableDictionary *selectTextAttrs = [NSMutableDictionary dictionary];
    selectTextAttrs[NSForegroundColorAttributeName] = kHexColor(0x1A1A1A);
    [childVc.tabBarItem setTitleTextAttributes:textAttrs forState:UIControlStateNormal];
    [childVc.tabBarItem setTitleTextAttributes:selectTextAttrs forState:UIControlStateSelected];
    
    // 解決出現(xiàn)系統(tǒng)藍(lán)問題    
    if(@available(iOS 13.0, *)) {
        UITabBarAppearance *appearance = [UITabBarAppearance new];
        // 設(shè)置未被選中的顏色
        appearance.stackedLayoutAppearance.normal.titleTextAttributes = @{NSForegroundColorAttributeName: kHexColor(0x939393)};
        // 設(shè)置被選中時(shí)的顏色
        appearance.stackedLayoutAppearance.selected.titleTextAttributes = @{NSForegroundColorAttributeName: kHexColor(0x1A1A1A)};
        [UITabBar appearance].standardAppearance = appearance;
    }
    [self addChildViewController:childVc];
}