iOS推送通知点击导致应用崩溃

Question

我的推送通知点击有问题。 每次用户单击通知时，应用程序将崩溃，而不是将用户重定向到指定页面。

这部分代码导致错误“无法将类型'appname.LaunchScreenController'的值强制转换为'UINavigationController'” ：

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

并且此代码将导致致命错误：解开Optional值时意外发现nil ：

 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)
}

提前致谢

Answer 1

RootViewController是UIViewController子类，而不是UINavigationController您必须处理null值

改成

let rootViewController = self.window!.rootViewController

Answer 2

我将代码更改为此并且现在可以正常工作

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)

}