在Xcode 11编译的tvOS 13应用中能否沿用tvOS9-12的UITabBarController默认UI？

Absolutely! tvOS 13 rolled out a fresh default design for UITabBarController, but you can easily revert to the classic tvOS 9-12 style using the UIBarAppearance APIs (introduced in tvOS 13, which Xcode 11 fully supports). Here's how to pull it off:

Option 1: Customize for a single UITabBarController #

If you only want one tab bar controller to use the legacy style, add this code to its viewDidLoad() method:

override func viewDidLoad() {
    super.viewDidLoad()
    
    // Create an appearance that matches tvOS 9-12's tab bar look
    let legacyTabBarAppearance = UITabBarAppearance()
    
    // Set the dark, muted background typical of older tvOS versions
    legacyTabBarAppearance.backgroundColor = UIColor(red: 0.1, green: 0.1, blue: 0.1, alpha: 1.0)
    
    // Style selected items (white icon/text, red badge)
    legacyTabBarAppearance.stackedLayoutAppearance.selected.iconColor = .white
    legacyTabBarAppearance.stackedLayoutAppearance.selected.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
    legacyTabBarAppearance.stackedLayoutAppearance.selected.badgeBackgroundColor = .systemRed
    
    // Style unselected items (gray icon/text)
    legacyTabBarAppearance.stackedLayoutAppearance.normal.iconColor = .gray
    legacyTabBarAppearance.stackedLayoutAppearance.normal.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.gray]
    
    // Apply the style to both standard and scroll-edge states
    tabBar.standardAppearance = legacyTabBarAppearance
    tabBar.scrollEdgeAppearance = legacyTabBarAppearance
}

Option 2: Apply the legacy style globally #

To make every UITabBar in your app use the old design, set this up in your AppDelegate's launch method:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    if #available(tvOS 13.0, *) {
        let legacyTabBarAppearance = UITabBarAppearance()
        // Replicate the same appearance config as above
        legacyTabBarAppearance.backgroundColor = UIColor(red: 0.1, green: 0.1, blue: 0.1, alpha: 1.0)
        legacyTabBarAppearance.stackedLayoutAppearance.selected.iconColor = .white
        legacyTabBarAppearance.stackedLayoutAppearance.selected.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.white]
        legacyTabBarAppearance.stackedLayoutAppearance.selected.badgeBackgroundColor = .systemRed
        legacyTabBarAppearance.stackedLayoutAppearance.normal.iconColor = .gray
        legacyTabBarAppearance.stackedLayoutAppearance.normal.titleTextAttributes = [NSAttributedString.Key.foregroundColor: UIColor.gray]
        
        UITabBar.appearance().standardAppearance = legacyTabBarAppearance
        UITabBar.appearance().scrollEdgeAppearance = legacyTabBarAppearance
    }
    return true
}

Quick Tips: #

• The UIBarAppearance API is exclusive to tvOS 13+, which aligns perfectly with your target version, so no compatibility hiccups here.
• Feel free to tweak the color values to match the exact shade of the old tvOS tab bar—adjust the backgroundColor and text/icon colors to your liking.
• Setting scrollEdgeAppearance ensures the style stays consistent even when content scrolls beneath the tab bar.

内容的提问来源于stack exchange，提问作者Daniel Storm