iOS-应用程式被杀死时，应用程式内的电子邮件连结开启无法正常运作

Question

在我的iOS应用中，我正在打开电子邮件中的链接。文件apple-app-site-association设置正确。为了处理链接，我在AppDelegate.swift中使用此功能：

func application(_ application: UIApplication, continue userActivity: NSUserActivity, restorationHandler: @escaping ([Any]?) -> Void) -> Bool {

    guard userActivity.activityType == NSUserActivityTypeBrowsingWeb,
        let url = userActivity.webpageURL,
        let components = URLComponents(url: url, resolvingAgainstBaseURL: true) else {
            return false
    }

    if (components.description.contains("/link1/")) {

        let mainStoryboardIpad : UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        let initialViewControlleripad : ViewNewPass = mainStoryboardIpad.instantiateViewController(withIdentifier: "NewPass") as! ViewNewPass
        initialViewControlleripad.activationUrl = components.description
        self.window = UIWindow(frame: UIScreen.main.bounds)
        self.window?.rootViewController = initialViewControlleripad
        self.window?.makeKeyAndVisible()
        return true

    } else if (components.description.contains("/link2/")) {

        let mainStoryboardIpad : UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        let initialViewControlleripad : ViewController = mainStoryboardIpad.instantiateViewController(withIdentifier: "Login") as! ViewController
        initialViewControlleripad.activationUrl = components.description
        self.window = UIWindow(frame: UIScreen.main.bounds)
        self.window?.rootViewController = initialViewControlleripad
        self.window?.makeKeyAndVisible()
        return true

    } else if (components.description.contains("/link3/")) {

        let mainStoryboardIpad : UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
        let initialViewControlleripad : ViewWrapper = mainStoryboardIpad.instantiateViewController(withIdentifier: "Wrapper") as! ViewWrapper
        initialViewControlleripad.memberActivation = components.description
        self.window = UIWindow(frame: UIScreen.main.bounds)
        self.window?.rootViewController = initialViewControlleripad
        self.window?.makeKeyAndVisible()
        return true

    } else {

        if let webpageUrl = URL(string: components.description) {
            application.open(webpageUrl)
        }
        return false

    }
}

当我的iOS应用仍在后台时，一切运行良好。应用程序被杀死后，我尝试打开电子邮件中的链接，我将被重定向到初始ViewController，而不是先前代码中设置的那个。是什么导致此问题？我该如何解决？