问题
For example, I would like to see the pre-Leopard API version of HID Explorer. I see in the revision history that the initial sample was created on 2003-01-14. Is there any way to get that revision?
回答1:
Sadly, no. Unless you have an older system restore disc (they came with older versions of Xcode and I think the documentation came with them) or one of the older ADC DVD mailings that went away in favor of online downloads.
回答2:
You can access older code samples through an older "documentation set". Documentation samples may have been bundled with Xcode in the past, but this is no longer the case. Downloading an older version of Xcode may be a waste, depending on how far back you want to go.
If you look at the answer to this question it will show you how to download an older documentation set. Xcode uses an ATOM feed to download / update documentation sets, so it's just a matter of adding the correct URL.
After downloading the documentation set you can search/view both versions in Window -> Organizer -> Documentation.
(In my case I wanted the older version of PhotoScroller. Since iOS 6.0, they changed the slider from a dequeing UIScrollView to a UIPageViewController).
来源：https://stackoverflow.com/questions/4543158/is-there-a-way-to-get-old-revisions-of-apple-sample-code