如何确认已为我的应用程序启用了iCloud备份？

Question

I have an iOS app that stores large amounts of data on the device. We rely on iCloud Backup to preserve data in case the user replaces or resets their device.

Unfortunately, users sometimes disable iCloud backup for just our app to save space on iCloud; then, months later, they attempt to restore data onto their new device but there's no app data to restore because they stopped backing it up.

I'd really, really like to be able to find out if the user has iCloud Backup checked for our particular app, so we can give users occasional alerts warning them that their data is not being backed up.

Is there any way to programmatically determine whether my app has the iCloud Backup slider set to ON or OFF?

Answer 1

看一下NSFileManager上的ubiquityIdentityToken属性，如果为您的应用设置并启用了iCloud，则该属性应该为非零。

Answer 2

You can't. That is because you don't say to iCloud Backup that you want your app to be backed up, it just takes NSUserDefaults and files (not flagged) from DocumentsDirectory and saves them. You could better write an Alert to give more information why is so important having this backup on and show her once.

Oh and please bear in mind that storing to iCloud non-user-generated content may lead to reject your app because:

Important : Apps should avoid mingling app data and user data in the same file. Doing so will unnecessarily increase backup sizes and can be considered a violation of the iOS Data Storage Guidelines.