Updated app has saved the original data

Question

What is the trick that some apps after update keep original data saved before update for example scores or settings. I would like to use it with pList, but have not found how yet.

tnx

Answer 1

Just save it to a file in your "Documents" folder, or use NSUserPreferences.

Both are retained across updates.

Answer 2

我希望NSUserDefaults能够正确处理它，但是我可能是错的。

Answer 3

There's no trick. Anything you save to user defaults or your app's documents directory will be preserved in an update.