iphone - dropbox如何在后台同步照片并获得苹果的认可？

Question

Dropbox 的最新更新允许在将应用程序置于后台后同步图片。苹果文档只允许某些后台进程。

音频、位置、voip、报摊内容、外部附件、蓝牙中心

Dropbox 不属于这些类别中的任何一个。

https://developer.apple.com/library/ios/#documentation/iphone/conceptual/iphoneosprogrammingguide/ManagingYourApplicationsFlow/ManagingYourApplicationsFlow.html

Answer 1

在上面链接的 iOS 应用程序编程指南中，查看副标题“在后台执行有限长度任务”下的“后台执行和多任务处理”部分:

Apps that are transitioning to the background can request an extra amount of time to finish any important last-minute tasks. To request background execution time, call the beginBackgroundTaskWithExpirationHandler: method of the UIApplication class. If your app moves to the background while the task is in progress, or if your app was already in the background, this method delays the suspension of your app. This can be important if your app is performing some important task, such as writing user data to disk or downloading an important file from a network server.

这为您提供了 10 分钟的后台时间来执行您想要的操作。如果您注意到，Dropbox 只会继续传输 10 分钟，然后您需要重新启动该应用才能继续。