Swift - 来自 appDelegate 的 pushViewController，rootViewController.navigationController 为 nil

Question

在遵循一些指南时遇到问题，特别是 http://blog.originate.com/blog/2014/04/22/deeplinking-in-ios/

我正在设置 url 方案，并且从另一个应用程序启动该应用程序运行良好，但传入主机或 url 并不能正常工作。我正在为所有视图布局使用故事板和界面构建器。

指南在 appDelegate 中显示了这个 openURL：

-(BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation{
    if([[url host] isEqualToString:@"page"]){
        if([[url path] isEqualToString:@"/page1"]){
            [self.mainController pushViewController:[[Page1ViewController alloc] init] animated:YES];
        }
    return YES;
    }
}

这是我从其他几个来源快速简化的版本，即 Get Instance Of ViewController From AppDelegate In Swift我目前正在跳过 url 主机的条件以删除问题中潜在的其他变量。

func application(application: UIApplication, openURL url: NSURL, sourceApplication: String, annotation: AnyObject?) -> Bool {
    var rootViewController = self.window!.rootViewController
    let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
    var profileViewController = mainStoryboard.instantiateViewControllerWithIdentifier("profile") as ProfileViewController

    rootViewController.navigationController.popToViewController(profileViewController, animated: true)

    return true

}

swift 版本导致崩溃： fatal error: unexpectedly found nil while unwrapping an Optional value

好像rootViewController还没有navigationController？

Answer 1

在我的例子中，rootViewController 似乎实际上是 UINavigationController 类型，因此在声明中强制转换它允许我直接在其上调用 pushToViewController。

func application(application: UIApplication, openURL url: NSURL, sourceApplication: String, annotation: AnyObject?) -> Bool {
    let rootViewController = self.window!.rootViewController as! UINavigationController
    let mainStoryboard = UIStoryboard(name: "Main", bundle: nil)
    let profileViewController = mainStoryboard.instantiateViewController(withIdentifier: "InstructionVC") as! InstructionVC
    rootViewController.pushViewController(profileViewController, animated: true)
    return true

}

Answer 2

SWIFT 4： 使用条件绑定和链接的安全推送方式

if let navController = self.navigationController, let viewController = self.storyboard?.instantiateViewController(withIdentifier: "indentfier") as? CustomViewController{
    navController.pushViewController(viewController, animated: true)
}

一行代码：

斯威夫特 3：

self.navigationController!.pushViewController(self.storyboar‌​d!.instantiateViewCo‌​ntroller(withIdentif‌​ier: "view2") as UIViewController, animated: true)

---

self.navigationController!.pushViewController(self.storyboard!.instantiateViewControllerWithIdentifier("view2") as UIViewController, animated: true)

Answer 3

APPDELEGATE 到页面：

        let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        let loginPageView = mainStoryboard.instantiateViewControllerWithIdentifier("leadBidderPagerID") as! LeadBidderPage
        var rootViewController = self.window!.rootViewController as! UINavigationController
        rootViewController.pushViewController(loginPageView, animated: true)

逐页：

        let loginPageView = self.storyboard?.instantiateViewControllerWithIdentifier("scoutPageID") as! ScoutPage
        self.navigationController?.pushViewController(loginPageView, animated: true)

Answer 4

为 swift 3/4 更新。 投票最多的“一行代码”不起作用，因为“self”中没有导航控制器

let rootViewController = self.window!.rootViewController as! 
UINavigationController
let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let profileViewController = mainStoryboard.instantiateViewController(withIdentifier: "ProfileViewController") as! ProfileViewController
rootViewController.pushViewController(profileViewController, animated: true)

Answer 5

从 AppDelegate 推送视图控制器的 Swift 3 和 4 最佳实践：

if let rootViewController = self.window!.rootViewController as? UINavigationController {
   let storyboard = UIStoryboard(name: "Main", bundle: nil)

   if let viewcontroller = storyboard.instantiateViewController(withIdentifier: "DiscussionBoardSID") as? DiscussionBoardViewController {
      viewcontroller.postID = "13" ///pass data to your viewcontroller
      rootViewController.pushViewController(viewcontroller, animated: true)
   }
}

Answer 6

如果你想用 NavigationBar 或 Dismiss(Animated: true, completion: nil) 来展示和关闭 在 didFinishLaunchingWithOptions

中设置 addObserver

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



NotificationCenter.default.addObserver(self, selector: #selector(devolucionNoPresencial), name: NSNotification.Name(rawValue: "DevolucionNoPresencial"), object: nil)
        return true
}

然后在你的方法中

func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
//do your code for .active, .inactive .background, etc

 if let userInfo = response.notification.request.content.userInfo as? [String : AnyObject] {
            if UIApplication.shared.applicationState == .active {
//activate the notificationCenter so you can call your @objc method
NotificationCenter.default.post(name: NSNotification.Name(rawValue: "DevolucionNoPresencial"), object: nil)
}

添加@objc方法

@objc private func devolucionNoPresencial() {


       //change DevolucionVC for VC you want to present

        if let controller = DevolucionVC() as? DevolucionVC {
            if let window = self.window, let rootViewController = window.rootViewController {
                var currentController = rootViewController
                while let presentedController = currentController.presentedViewController {
                    currentController = presentedController
                }
                currentController.present(controller, animated: true, completion: nil)
            }
        }

    }

}

Answer 7

func pushNewView() {
    if let wind = UIApplication.sharedApplication().delegate?.window {
        if let rootViewController = wind?.rootViewController {
            let viewToPush = YourViewController()
            let nav1 = UINavigationController(rootViewController: viewToPush)
            if let alreadySomeOneThere = rootViewController.presentedViewController {
                alreadySomeOneThere.presentViewController(nav1, animated: true, completion: nil)
            }else {
                rootViewController.presentViewController(nav1, animated: true, completion: nil)
            }
        }
    }
}