iOS13不支持后台更新通知吗？

Question

iOS13不支持后台更新通知。这是操作系统级别的错误吗？
当应用进入后台时，Xcode警告显示:

Can't end BackgroundTask: no background task exists with identifier 1 (0x1), or it may have already been ended. Break in UIApplicationEndBackgroundTaskError() to debug.

Answer 1

我从开发人员文档中得到了答案:
https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/sending_notification_requests_to_apns

apns-push-type

(Required when delivering notifications to devices running iOS 13 and later, or watchOS 6 and later. Ignored on earlier system versions.) The type of the notification. The value of this header is alert or background. Specify alert when the delivery of your notification displays an alert, plays a sound, or badges your app's icon. Specify background for silent notifications that do not interact with the user.