ios - CKQuery订阅 : Failing to Make Subscription

Question

我有一个正在使用 CloudKit 开发的 iOS 应用程序。我正在尝试订阅。

import CloudKit

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") // TRUEPREDICATE: all records of the specified type match the predicate
        let subscription = CKQuerySubscription(recordType: "PrivateRecords", predicate: predicate, options: .firesOnRecordCreation)
        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)")
            }
        }))
    }
}

而且它会一直出错。错误说明如下。

Subscription with a nil notificationInfo: CKQuerySubscription: 0x7fd7bfca7ec0; ; Query Subscription: recordType=PrivateRecords, predicate=TRUEPREDICATE, subscriptionOptions=1, subscriptionID=728863F8-3852-4A12-B5C6-F65EC945207A, zoneID=(null)

我可以根据订阅 ID 删除订阅。但是每次我运行这个应用程序时它都会给我一个不同的 ID。实际上，我已经对 ma​​cOS 应用程序做了同样的事情。它有一个订阅。此外，我大约一周前删除了一个订阅类型，看看会发生什么。我真的不知道订阅 ID 有什么用。

那么我在订阅时做错了什么？谢谢。

Answer 1

CKQuerySubscriptions 有一个属性 notificationInfo，你需要做的是像下面这样的事情:

let notification = CKSubscription.NotificationInfo()
notification.alertBody = "You have a new message"
notification.shouldSendContentAvailable = true

newSubscription.notificationInfo = notification