Question

如果我有两个viewControllers，我希望当条件成功时，我想转到另一个ViewController。

但我想每次启动应用程序时检查，所以我将值存储在userDefaults上，并在appDelegate中检查了该值。

当我打印该值时，我得到它但我无法转到所需的控制器。

func application(_ application: UIApplication,
                 didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {


    let active:Bool = defaults.bool(forKey: "activeBooking")

    if active {

        print("active \(active)")

        let rootViewController = self.window!.rootViewController
        let mainStoryboard: UIStoryboard = UIStoryboard(name: "Final", bundle: nil)
        let setViewController = mainStoryboard.instantiateViewController(withIdentifier: "finalBooking") as! BookingFromCurrentLocationVC
        rootViewController?.navigationController?.popToViewController(setViewController, animated: false)

    }
    return true
}

我在其他控制器中打印该值并返回true（我的值）所以为什么我不能去另一个控制器

Answer 1

你可以试试这个：

在appDelegate和didFinishLaunching

中

您可以将此值存储在UserDefault中，然后检查条件：

if condition == true{
 goToVC1()
}else{
 goToVC2
}



func goToVC1() {
let storyboard:UIStoryboard = UIStoryboard(name: "Main", bundle: Bundle.main)
let ObjVC1: ViewController = storyboard.instantiateViewController(withIdentifier: "VC1") as! VC1
let navigationController : UINavigationController =   UINavigationController(rootViewController: ObjVC1)
self.window?.rootViewController = navigationController
self.window?.makeKeyAndVisible()
}

 func goToVC2() {
    let storyboard:UIStoryboard = UIStoryboard(name: "Main", bundle: Bundle.main)
    let ObjVC2: ViewController = storyboard.instantiateViewController(withIdentifier: "VC2") as! VC2
    let navigationController : UINavigationController =   UINavigationController(rootViewController: ObjVC2)
    self.window?.rootViewController = navigationController
    self.window?.makeKeyAndVisible()
    }

Answer 2

将一个segue从导航控制器添加到所需的View Controller（带有segue标识符“finalBookingVC”），并将if条件中的代码替换为：

self.window?.rootViewController!.performSegue(withIdentifier: "finalBookingVC", sender: nil)

Answer 3

您可以在AppDelegate中启动视图控制器，如下所示。执行条件检查并根据您的要求设置StoryboardID和ViewControllerID。

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    self.window = UIWindow(frame: UIScreen.main.bounds)
    //check your condition here and change the Storyboard name and ViewController ID as required
    let vc = UIStoryboard.init(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "HomeVCID") as! HomeController
    self.window?.rootViewController = vc
    self.window?.makeKeyAndVisible()
    return true
}

Answer 4

首先需要检查应用程序是否处于活动状态并且已经打开（顶部控制器是finalBookingVC），然后无需执行任何操作，

第二件事finalBookingVC如果已经在堆栈中可用，那么当时不需要推送你需要弹出视图控制器。

如果堆栈上没有finalBookingVC，那么你需要推动这个控制器。

func gotoController() {
            let navigationController : UINavigationController! = self.window!.rootViewController as! UINavigationController;
            let arrViewController = navigationController;
            if arrViewController != nil && !(arrViewController?.topViewController is finalBookingVC) {
                var finalBookingVCFound:Bool = false;
                for aViewController in (arrViewController?.viewControllers)! {
                    if aViewController is finalBookingVC {
                        finalBookingVCFound = true;
                        _ = navigationController?.popToViewController(aViewController, animated: true);
                        break;
                    }
                }
                if !finalBookingVCFound {
                    let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil);
                    let objVC:finalBookingVC = mainStoryboard.instantiateViewController(withIdentifier: "finalBookingVC") as! finalBookingVC;
                    navigationController?.pushViewController(objVC, animated: true);
                }
            }
    }

如何从appDelegate转到viewController

4 个答案: