iOS推送通知 - 无法保证

Question

我已从本教程制作了PushChatStarter应用程序，用于推送通知 http://www.raywenderlich.com/32963/apple-push-notification-services-in-ios-6-tutorial-part-2

但我发现只有部分消息被成功发送。在教程中提到推送通知不能保证。我想知道发生这种情况的原因。

我无法理解该教程中提到的解决方案。任何人都可以解释如何获得解决方案。我想知道如何使应用程序可靠。

Answer 1

我在这里找到答案：https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Chapters/WhatAreRemoteNotif.html

Quality of Service

Apple Push Notification Service includes a default Quality of Service (QoS) component that
performs a store-and-forward function. If APNs attempts to deliver a notification but the      device 
is offline, the QoS stores the notification. It retains only one notification per application 
on a device: the last notification received from a provider for that application. 
When the offline device later reconnects, the QoS forwards the stored notification to the device.
The QoS retains a notification for a limited period before deleting it.