ios - 如何在非 UIView 类的 uiView 之间切换

Question

情况是这样的。我有一个应用程序，它呈现一个 tabBarController 作为其 Root View Controller ，并带有许多 tabItems。这是我的应用程序委托(delegate)中的设置

class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

        let vc1 = VC1(nibName: "VC1", bundle: nil)
        let vc2 = VC2(nibName: "VC2", bundle: nil)

        let menuTabBarController = MenuTabBarController(nibName: "MenuTabBarController", bundle: nil)
        menuTabBarController.viewControllers = [VC1,VC2]

        window = UIWindow(frame: UIScreen.mainScreen().bounds)
        window?.rootViewController = menuTabBarController
        window?.makeKeyAndVisible()

        //Setup tab bar
        UITabBar.appearance().barTintColor = UIColor.blackColor()

        let IMG1 = UIImage(named: "img2.png")
        let IMG2 = UIImage(named: "img2.png")

        VC1.tabBarItem = UITabBarItem(
        title: "View 1",
            image: IMG1,
            tag: 1)
        VC2.tabBarItem = UITabBarItem(
            title: "View 2",
            image: IMG2,
            tag:2)



        return true
    }

    func applicationWillResignActive(application: UIApplication) {

    }

    func applicationDidEnterBackground(application: UIApplication) {

    }


}

所以请注意，我有两个 UIViewController 类(VC1 和 VC2)嵌套在 menuTabBar 中。现在，从 menuTabBar 类，我可以轻松地在 View 之间切换，如下所示

    class MenuTabBarController: UITabBarController,UITabBarControllerDelegate{

        override func viewDidLoad() {
            super.viewDidLoad()

            self.delegate = self//Set tabbarcontroller delegate

        }

        // UITabBarControllerDelegate
        func tabBarController(tabBarController: UITabBarController, didSelectViewController viewController: UIViewController) {
            tabBarController.selectedIndex = 1;//Say I wanted to transition to VC2
        }

    }

但我最终想要做的是能够从另一个不是 UIViewController 的类在两个 UIViewController 之间切换。我尝试过这样的事情

    class Actions(){
        func someFunctionThatSwitchesToVC2(){
            //So I create a reference to appDelegate which in turn, is supposed to reference the tab bar and switch between its child views

            let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate

            let tabBarController: UITabBarController = (appDelegate.window?.rootViewController as? UITabBarController)!
            tabBarController.selectedIndex = 1
        }
    }

当我运行 someFucntionThatSwitchesToVC2 时，出现此错误“ fatal error :索引超出范围”。显然我没有做正确的事情。任何想法都非常感激PS，当我执行 tabBarController.selectedIndex = 0 时，我没有收到错误，但什么也没有发生

Answer 1

我认为您在分配 ViewController 时犯了拼写错误。更改此行:

menuTabBarController.viewControllers = [VC1,VC2]

下面一行:

menuTabBarController.viewControllers = [vc1,vc2]