Getting notifications on changes to the iPhone Address book

In my iPhone app, I have a collection of contacts from the iPhone address book, whose ABRecordIDs are stored via Core Data. I want to 开发者_开发技巧keep track of any changes made to them in and out of my app. Currently, on startup, I loop through all the ABRecordIDs I have, checking for any updates. This is horribly inefficient, of course.

Is there a better way to do this? I'm looking at ABAddressBookRegisterExternalChangeCallback, but I'm wondering if this will report changes made outside of my app. For example, if I exit the app, edit one or more contacts in the addressbook, and then reopen the app, will I get a notification of the changes?

Any help would be very much appreciated! Thanks in advance!

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My immediate suspicion is that you will, provided your app is backgrounded. If it exits (or gets killed), then of course you won't get the callbacks.