在应用程序设置页面更改通知的用户权限时更新 UILabel 文本值？

Question

在我的场景中，用户会在应用程序中收到通知通知。如果用户单击“不允许”，UILabel 会更新为“未启用”。如果用户想要更改通知，用户将被导航到应用程序设置页面以更改通知权限状态。

func checkNotificationPermission(){

UNUserNotificationCenter.current().requestAuthorization(options:[.badge, .alert, .sound]){


        (granted, error) in

        if granted == true {

            DispatchQueue.main.async {
                    print("notificaation access true")
                     self.notificationAccessLbl?.text = "Enabled"         
        }
        }
        else {
            DispatchQueue.main.async {
                self.notificationAccessLbl?.text = "Not enabled" 
            }
        } 
    }
    UIApplication.shared.registerForRemoteNotifications() }

但是当用户返回应用程序时，当用户从设置页面返回应用程序时，UILabel 没有得到更新。

用于在用户从设置页面到应用程序后更新应用程序中的 UILabel。我打过电话

func checkNotificationPermission()

更新 ViewDidAppear() 方法中的 UILabel 值，我在 applicationwillbecomeactive method() 中注册了一个函数，请帮助我。

Answer 1

我在应用程序的设置页面中有开关，允许用户启用禁用推送并将在服务器上发送，但在该用户必须允许从设备的设置页面推送之前。这是我的解决方案

我已经创建了全局对象

var isPushEnabledFromSettings = false {
    didSet {
         // you can set label value here in main queue
    }
}

还有一种检查方法

func isPushPermissionGiven (permission:@escaping (Bool) -> ()) {
    if #available(iOS 10.0, *) {
        let current = UNUserNotificationCenter.current()
        current.getNotificationSettings(completionHandler: {settings in
            switch settings.authorizationStatus {
            case .notDetermined:
                permission(false)
            case .denied:
                permission(false)
            case .authorized:
                permission(true)
            }
        })
    } else {
        // Fallback on earlier versions
        if UIApplication.shared.isRegisteredForRemoteNotifications {
            permission(true)


        } else {
            permission(false)

        }
    }
}

并且在视图中确实加载了这些行

    self.isPushPermissionGiven { (permission) in
        self.isPushEnabledFromSettings = permission
    }

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

        strongSelf.isPushPermissionGiven { (permission) in
            DispatchQueue.main.async {
                strongSelf.isPushEnabledFromSettings = permission
            }
        }
    }

现在我在设置页面中有开关，允许用户启用禁用推送

@objc func switchChanged (sender:UISwitch) {

    guard self.isPushEnabledFromSettings else {
        AppDelegate.sharedDelegate.navigateUesrToSettings(withMessage: "Please grant push permission from settings")
        DispatchQueue.main.asyncAfter(deadline: .now() + 0.5, execute: {
            sender.setOn(false, animated: false)
        })
        return

    }
}



  func navigateUesrToSettings (withTitle title:String = "YourApp", withMessage message:String) {
        let alertController = UIAlertController (title: title, message: message, preferredStyle: .alert)

        let settingsAction = UIAlertAction(title: "Settings", style: .default) { (_) -> Void in
            guard let _ = URL(string: UIApplicationOpenSettingsURLString) else {
                return
            }

            self.navigate(To: UIApplicationOpenSettingsURLString)

        }
        alertController.addAction(settingsAction)
        let cancelAction = UIAlertAction(title: "Cancel", style: .default, handler: nil)
        alertController.addAction(cancelAction)

        AppDelegate.sharedDelegate.window?.rootViewController?.present(alertController, animated: true, completion: nil)
    }

希望对你有帮助:)