2.23 Apps must follow the iOS Data Storage Guidelines or they will be rejected

国庆前提交审核的App，今天被苹果rejected回来。查了一下原因。

以下是苹果拒绝原文。

----- 2.23 -----

We found that your app does not follow the
iOS Data Storage Guidelines, which is required per theApp Store Review Guidelines.

In particular, we found that on launch and/or content download, your app stores 2.03MB. To check how much data your app is storing:

- Install and launch your app
- Go to Settings > iCloud > Storage & Backup > Manage Storage
- If necessary, tap "Show all apps"
- Check your app's storage

The iOS Data Storage Guidelines indicate that only content that the user creates using your app, e.g., documents, new files, edits, etc., should be backed up by iCloud.

Temporary files used by your app should only be stored in the /tmp directory; please remember to delete the files stored in this location when the user exits the app.

Data that can be recreated but must persist for proper functioning of your app - or because customers expect it to be available for offline use - should be marked with the "do not back up" attribute. For NSURL objects, add the
NSURLIsExcludedFromBackupKey attribute to prevent the corresponding file from being backed up. For CFURLRef objects, use the corresponding kCFURLIsExcludedFromBackupKey attribute.

For more information, please see
Technical Q&A 1719: How do I prevent files from being backed up to iCloud and iTunes?.

It is necessary to revise your app to meet the requirements of the iOS Data Storage Guidelines.
For discrete code-level questions, you may wish to consult withApple Developer Technical Support.
When the DTS engineer follows up with you, please be ready to provide:

- complete details of your rejection issue(s)
- screenshots
- steps to reproduce the issue(s)
-
symbolicated crash logs - if your issue results in a crash log

If you have difficulty reproducing a reported issue, please try testing the workflow as described in <https://developer.apple.com/library/ios/qa/qa1764/>Technical
Q&A QA1764: How to reproduce a crash or bug that only App Review or users are seeing.

分析原因：

每个安装应用的app都有一个document文件夹，这个文件夹下面的文件会自动备份到iCloud。

1、在我们的app中，当用户首次安装完启动，会自动保存log在documents目录下，导致文件过大。

2、应用中也会加载一些配置文件和图片也都会放置在这个文件夹下

解决方案：

1、根据苹果的官方文档：
https://developer.apple.com/library/ios/qa/qa1719/_index.html
按照文档描述，需要给文件添加属性

NSURLIsExcludedFromBackupKey
or
kCFURLIsExcludedFromBackupKey
2、可以把一些不必要的文件放置在缓存中。

Library/Caches

参考文档： http://stackoverflow.com/questions/16239147/ios-do-not-back-up-attribute