Question

我在 didFinishLaunchingWithOptions 中有这段代码：

    window = UIWindow(frame: UIScreen.mainScreen().bounds)
    let tabBarController = UITabBarController()

    let listTableViewController = ListTableViewController()
    listTableViewController.tabBarItem = UITabBarItem(tabBarSystemItem: .Contacts, tag: 0)
    var navViewController = UINavigationController(rootViewController: listTableViewController)
    tabBarController.viewControllers?.append(navViewController)

    let galleryViewController = GalleryViewController()
    galleryViewController.tabBarItem = UITabBarItem(tabBarSystemItem: .Featured, tag: 1)
    navViewController = UINavigationController(rootViewController: galleryViewController)
    tabBarController.viewControllers?.append(navViewController)

    let serviceViewController = ServiceViewController()
    serviceViewController.tabBarItem = UITabBarItem(tabBarSystemItem: .More, tag: 2)
    navViewController = UINavigationController(rootViewController: serviceViewController)
    tabBarController.viewControllers?.append(navViewController)

    tabBarController.selectedIndex = 0
    window?.rootViewController = tabBarController
    window?.makeKeyAndVisible()
    return true

但是，当应用程序启动并且徽标消失时，我只有黑屏并且标签栏上没有标签，但我想至少看到ListTablevViewController中的空表视图。

Answer 1

我下载了你的项目，似乎viewControllers的附加功能无法正常工作，因为tabBarController.viewControllers在某种程度上是零。我做了这个小测试，效果很好：

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        window = UIWindow(frame: UIScreen.mainScreen().bounds)
        let tabBarController = UITabBarController()

        let listTableViewController = ListTableViewController()
        listTableViewController.tabBarItem = UITabBarItem(tabBarSystemItem: .Contacts, tag: 0)
        let navViewController = UINavigationController(rootViewController: listTableViewController)
        tabBarController.viewControllers?.append(navViewController)

        let galleryViewController = GalleryViewController()
        galleryViewController.tabBarItem = UITabBarItem(tabBarSystemItem: .Featured, tag: 1)
        let navViewController1 = UINavigationController(rootViewController: galleryViewController)
        tabBarController.viewControllers?.append(navViewController)

        let serviceViewController = ServiceViewController()
        serviceViewController.tabBarItem = UITabBarItem(tabBarSystemItem: .More, tag: 2)
        let navViewController2 = UINavigationController(rootViewController: serviceViewController)
        tabBarController.viewControllers?.append(navViewController)

        let controllers = [navViewController, navViewController1, navViewController2]

        tabBarController.selectedIndex = 0
        tabBarController.viewControllers =  controllers
        window!.rootViewController = tabBarController
        window!.makeKeyAndVisible()


        return true
    }

TabBar黑屏，没有标签

1 个答案: