CloudKit在记录创建时接收多个通知

Question

我正在使用FireOnCreation添加对Cloud Kit记录类型的订阅。

在appDelegate中，我使用didReceiveRemoteNotificationWithCompletionHandler来捕获通知。我遇到的问题是当创建与谓词匹配的记录时，didReceiveRemoteNotificationWithCompletionHandler会触发多次。在设备A上，它将一致地触发3次，而在设备B上，它将触发6次。我甚至试图在Cloud DashBoard上创建一个记录，它仍然可以做同样的事情。所以这说明问题不在于创建记录。任何建议或提示都会有很大的帮助。

func application(application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject : AnyObject], fetchCompletionHandler completionHandler: (UIBackgroundFetchResult) -> Void) {
}

func subscribeRecordChangesForCurrentUser(userRecordID: CKRecordID) {
    print("subscribeRecordChangesForCurrentUser \(userRecordID.recordName)")
    let userRef = CKReference(recordID: userRecordID, action: CKReferenceAction.None)
    let predicate = NSPredicate(format: "toUsers CONTAINS %@", userRef)
    let subscription = CKSubscription(recordType: "Track", predicate: predicate, options: [.FiresOnRecordCreation])

    let notificationInfo = CKNotificationInfo()
    notificationInfo.alertBody = "Created a new track."
    notificationInfo.shouldSendContentAvailable = true
    notificationInfo.soundName = UILocalNotificationDefaultSoundName

    subscription.notificationInfo = notificationInfo

    let publicDatabase = CKContainer.defaultContainer().publicCloudDatabase

    publicDatabase.saveSubscription(subscription) { (subscription: CKSubscription?, error: NSError?) -> Void in
        guard error == nil else {
            print(error?.localizedDescription)
            return
        }
        print("successfully subscript user")
    }
}