ios - 如果请求通知权限，请选中推送

Question

我已经看过Determine on iPhone if user has enabled push notifications

但我的问题有些不同。如果用户拒绝推送通知权限，我需要显示“导航到设置”屏幕。我们如何检查之前是否已请求过推送权限？ if#available(iOS 10.0, *) { 工作正常，并且能够获取所有 status，但对于早期版本，我无法弄清楚。

我有以下代码:

    NotificationCenter.default.addObserver(forName: NSNotification.Name.UIApplicationDidBecomeActive, object: nil, queue: .main) {[weak self] (notificaiont) in
        guard let strongSelf = self  else {return }

        if #available(iOS 10.0, *) {
            let current = UNUserNotificationCenter.current()
            current.getNotificationSettings(completionHandler: {settings in

                switch settings.authorizationStatus {
                case .notDetermined:
                    AppDelegate.sharedDelegate.registerForPush()
                case .denied:
                    AppDelegate.sharedDelegate.navigateUesrToSettings(withMessage: "Allow app to send notifications")
                case .authorized:
                    strongSelf.dismiss(animated: true, completion: nil)
                    break
                }
            })
        } else {
            // Fallback on earlier versions
            if UIApplication.shared.isRegisteredForRemoteNotifications {
                strongSelf.dismiss(animated: true, completion: nil)
            } else {
                //what should i call here  registerForPush for navigate to setting ?
               // AppDelegate.sharedDelegate.registerForPush()
                AppDelegate.sharedDelegate.navigateUesrToSettings(withMessage: "Allow app to send notifications")

            }
        }
    }

在 //Fallback on previous versions 的 else 部分我很困惑，我需要调用

AppDelegate.sharedDelegate.registerForPush()

或

AppDelegate.sharedDelegate.navigateUesrToSettings(withMessage: "允许应用发送通知")

？谢谢!

Answer 1

您必须自己存储它，例如在用户默认值中。当您提示用户授予权限时，将标志设置为true；像这样的东西:

if UIApplication.shared.isRegisteredForRemoteNotifications {
  // equivalent to .authorized case
}
else if !UserDefaults.standard.bool(forKey: "didAskForPushPermission") 
{
  // equivalent to .notDetermined case
  UserDefaults.standard.set(true, forKey: "didAskForPushPermission")
}
else {
  // equivalent to .denied case
}