iPad端TabBar未选中项颜色不生效，iPhone端正常（Xcode14.3.1）

针对Xcode 14.3.1、最低部署目标iOS 12.0的场景，iPad端TabBar未选中项颜色不生效的核心原因是：iPad上的UITabBar在部分布局场景（如分屏、悬浮窗口）下会优先使用scrollEdgeAppearance，若仅配置standardAppearance，未选中状态的颜色设置可能不会生效。以下是具体解决方案：

方案1：全局配置TabBar外观 #

在App启动时统一设置全局TabBar的外观属性，确保iPhone和iPad都生效：

// 可放在AppDelegate的application(_:didFinishLaunchingWithOptions:)或SceneDelegate的scene(_:willConnectTo:options:)中
let tabBarAppearance = UITabBarAppearance()

// 配置选中项颜色
tabBarAppearance.stackedLayoutAppearance.selected.iconColor = .systemBlue
tabBarAppearance.stackedLayoutAppearance.selected.titleTextAttributes = [.foregroundColor: UIColor.systemBlue]

// 配置未选中项颜色
tabBarAppearance.stackedLayoutAppearance.normal.iconColor = .lightGray
tabBarAppearance.stackedLayoutAppearance.normal.titleTextAttributes = [.foregroundColor: UIColor.lightGray]

// 同时设置standardAppearance和scrollEdgeAppearance，覆盖iPad的特殊布局场景
UITabBar.appearance().standardAppearance = tabBarAppearance
UITabBar.appearance().scrollEdgeAppearance = tabBarAppearance

方案2：在自定义TabBarController中单独配置 #

如果仅需针对特定TabBarController设置，可在其viewDidLoad中配置：

class CustomTabBarController: UITabBarController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let appearance = UITabBarAppearance()
        // 配置选中状态
        appearance.stackedLayoutAppearance.selected.iconColor = .yourSelectedColor
        appearance.stackedLayoutAppearance.selected.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.yourSelectedColor]
        // 配置未选中状态
        appearance.stackedLayoutAppearance.normal.iconColor = .yourUnselectedColor
        appearance.stackedLayoutAppearance.normal.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.yourUnselectedColor]
        
        // 绑定到当前TabBar
        tabBar.standardAppearance = appearance
        tabBar.scrollEdgeAppearance = appearance
        
        // 兼容iOS 12（最低部署为12.0，此部分可选）
        if #available(iOS 13.0, *) {} else {
            tabBar.tintColor = .yourSelectedColor
            tabBar.unselectedItemTintColor = .yourUnselectedColor
        }
    }
}

注意事项 #

• 避免单独使用unselectedItemTintColor：在iOS 13+的iPad上，UITabBarAppearance的配置优先级高于旧属性，单独设置可能被覆盖。
• 检查是否有局部覆盖：确保没有在单个UITabBarItem的代码中单独设置image或titleTextAttributes，否则会覆盖全局外观配置。

内容的提问来源于stack exchange，提问作者Chander Dhiman