ios - pushRegistry :didUpdate:pushCredentials not being called

Question

查看了过去关于此的问题，但这些问题的答案已应用于我的项目，但未调用 pushRegistry() 委托(delegate)方法。

首先是代码:

import UIKit
import PushKit
import UserNotifications

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate{

    var window: UIWindow?
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        let notificationSettings  = UIUserNotificationSettings(types: [.badge, .sound, .alert], categories: nil)
        application.registerUserNotificationSettings(notificationSettings)

        UNUserNotificationCenter.current().delegate = self
        UIApplication.shared.registerForRemoteNotifications()

        let voipRegistry = PKPushRegistry(queue: DispatchQueue.main)
        voipRegistry.desiredPushTypes = Set([PKPushType.voIP])
        voipRegistry.delegate = self;

        return true
    }
...
}

extension AppDelegate: PKPushRegistryDelegate {
    func pushRegistry(_ registry: PKPushRegistry, didUpdate pushCredentials: PKPushCredentials, for type: PKPushType) {
        NSLog("voip token: \(pushCredentials.token)")
    }

已启用以下应用程序功能:- 推送通知- 背景模式- 后台获取- 远程通知

我正在使用 Xcode 9.1 Beta，它不再将 Voip 作为一项显式功能，显然这不再需要，导入 PushKit 就足够了。

在配置门户上，已为应用程序 ID 启用推送通知。(已经生成了一个 Void Push 证书，但显然还不能用它来发送推送)

Answer 1

apparently this is no longer needed and importing PushKit should suffice.

我读了几篇帖子说这个，但它不正确。为了让事情正常进行，我必须手动编辑 info.plist 以将 voip 添加到背景模式列表中。

 <string>voip</string>

Apple 在玩什么？如果仍然需要，为什么他们将其从 Xcode 中删除？