AppDelegate从未为CKQuerySubscription调用过它的didReceiveRemoteNotification

Question

我试图让iOS应用程序听到CKQuerySubscription的变化。数据由远程iOS应用程序传输。我已经有了一个macOS应用程序，它确实接收远程iOS应用程序发送的数据。我遇到麻烦的iOS应用程序已经订阅了。然而，它的AppDelegate从未在didReceiveRemoteNotification方法中接收到调用。

import UIKit
import UserNotifications
import CloudKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate {
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        /* notifications */
        let center  = UNUserNotificationCenter.current()
        center.delegate = self
        UNUserNotificationCenter.current().getNotificationSettings { (settings) in
            switch settings.authorizationStatus {
            case .authorized:
                print("You already have permission")
                DispatchQueue.main.async() {
                    application.registerForRemoteNotifications()
                }
            case .denied:
                print("setting has been disabled")
            case .notDetermined:
                print("Let me ask")
                UNUserNotificationCenter.current().requestAuthorization(options: []) { (granted, error) in
                    if error == nil {
                        if granted {
                            print("you are granted permission")
                            DispatchQueue.main.async() {
                                application.registerForRemoteNotifications()
                            }
                        }
                    }
                }
            }
        }
        return true
    }
}

    func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
        print("Failed to register notifications_ error:", error)
    }

    func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
        print("Receiving data...") // never called...
    }
}

我有如下所示的一些功能。我不知道这个应用程序是否需要push notifications。现在，它打开了。

那么，为什么我的iOS应用程序没有接到远程通知电话呢？我用的是一个实际的设备，而不是模拟器。谢谢。

​

​

编辑：创建对记录更改的订阅

class HomeViewController: UIViewController {
    override func viewDidLoad() {
        registerSubscription()
    }

    func registerSubscription() {
        let cloudContainer = CKContainer(identifier: "iCloud.com.xxx.XXXXX")
        let privateDB = cloudContainer.privateCloudDatabase
        let predicate = NSPredicate(format: "TRUEPREDICATE")
        let subscription = CKQuerySubscription(recordType: "PrivateRecords", predicate: predicate, options: .firesOnRecordCreation)
        let notification = CKNotificationInfo()
        subscription.notificationInfo = notification
        privateDB.save(subscription, completionHandler: ({returnRecord, error in
            if let err = error {
                print("Subscription has failed: \(err.localizedDescription)")
            } else {
                print("Subscription set up successfully")
                print("Subscription ID: \(subscription.subscriptionID)")
            }
        }))
    }
}

Answer 1

还有几件事你可以检查。

首先，确保在应用程序委托中实现didReceiveRemoteNotification：

func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any]) {  
  let dict = userInfo as! [String: NSObject]
  let notification = CKNotification(fromRemoteNotificationDictionary: dict)

  if let sub = notification.subscriptionID{
    print("iOS Notification Received: \(sub)")
  }
}

还有一些其他的事情你可以检查：

1. 尝试删除CKQuerySubscription仪表板中的CloudKit，然后再次运行注册它的iOS代码。订阅是否出现在仪表板上？
2. CloudKit日志是否显示已发送通知？它列出了所有被推送到设备上的通知。
3. 如果您使用的是静默推送通知，请尝试在后台模式功能中启用后台获取(就在远程通知之上)。

如果您这样做了，但仍然不能工作，您能共享您的CKQuerySubscription代码吗？

--更新--

尝试在CKNotificationInfo对象上设置一些附加属性。有些带有通知的模糊bug通常可以通过设置以下几个属性来规避：

notification.shouldSendContentAvailable = true
notification.alertBody = "" //(Yes, a blank value. It affects the priority of the notification delivery)

您还可以尝试将谓词设置为：NSPredicate(value: true)

另外，您的privateDB.save方法返回什么？它说它成功还是失败？