Question

在AppDelegate之外，我想更改它的rootViewController。换句话说，我想在窗口中放置一个新的导航控制器，然后将其推入该导航控制器中：

func JumpToPage(_ controller: UIViewController) {
        guard let rootController = AppDelegate.shared?.presentationViewController else {
            return
        }
        let navigationController = UINavigationController(rootViewController: rootController)
        navigationController.pushViewController(controller, animated: true)
        AppDelegate.shared?.window?.rootViewController = navigationController
    }
}

但是此功能导致应用程序崩溃并显示以下错误消息：

Terminating app due to uncaught exception 'UIViewControllerHierarchyInconsistency',
    reason: 'adding a root view controller <MyExampleController> as a child of view controller:<UINavigationController>'

我应该如何解决？

Answer 1

从

更改

let navigationController = UINavigationController(rootViewController: rootController)

收件人

let navigationController = UINavigationController(rootViewController: controller)

更新

func JumpToPage(_ controller: UIViewController) {
    guard let rootController = AppDelegate.shared?.presentationViewController else {
        return
    }
    let navigationController = UINavigationController(rootViewController: controller)
    AppDelegate.shared?.window?.rootViewController = navigationController
}

Answer 2

我没有尝试替换导航控制器，而是按如下方式替换了初始导航控制器中的根VC。

在AppDelegate中：

func application(_ application: UIApplication, didFinishLaunchingWithOptions ...) {
    let storyboard = UIStoryboard(name: "FirstVC", bundle: Bundle.main)
    let firstViewController = instantiateInitialViewController()! as! FirstViewController
    navigationController = UINavigationController(rootViewController: firstViewController)
    window = UIWindow(frame: UIScreen.main.bounds)
    window!.rootViewController = navigationController
    window!.makeKeyAndVisible()
    return true
}

然后，我在FirstViewController中更改根VC，如下所示：

func someFuncInFirstVC() {
    let allControllers = NSMutableArray(array: self.navigationController!.viewControllers)
    allControllers.removeObject(at: allControllers.count - 1)  // remove root VC, count should be one...
    let secondViewController = SecondViewController()
    allControllers.add(secondViewController as AnyObject)  // this becomes new root VC since nav stack is empty now
    navigationController!.setViewControllers(allControllers as [AnyObject] as! [UIViewController], animated: true)
}

更改AppDelegate的根视图控制器会导致UIViewControllerHierarchyInconsistency异常

2 个答案: