iOS推送通知点击导致应用崩溃

Question

I am having an issue with my push notification click. Everytime user clicks on the notifications, the app will crash instead of redirecting user to the specified page.

This part of the code is causing an error "Could not cast value of type 'appname.LaunchScreenController' to 'UINavigationController'" :

let rootViewController = self.window!.rootViewController as! UINavigationController

And this code will cause fatal error: unexpectedly found nil while unwrapping an Optional value :

 func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {
    //receive the notifications
    NotificationCenter.default.post(name: Notification.Name(rawValue: "MyNotificationType"), object: nil, userInfo: userInfo)
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let vc = storyboard.instantiateViewController(withIdentifier: "NewsController") as! NewsViewController
    let rootViewController = self.window!.rootViewController as! UINavigationController
    rootViewController.pushViewController(vc, animated:true)
}

Thanks in advance

Answer 1

RootViewController is subclass of UIViewController not a UINavigationController You have to handle your null values

change to

let rootViewController = self.window!.rootViewController

Answer 2

I change the code to this and it works just fine now

func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {
    NotificationCenter.default.post(name: Notification.Name(rawValue: "MyNotificationType"), object: nil, userInfo: userInfo)
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let vc = storyboard.instantiateViewController(withIdentifier: "NewsController") as! NewsViewController
    let nav  = UINavigationController()
    nav.pushViewController(vc, animated: true)

}