问题
I did a search here already, and haven't found a clear answer to my question, so I thought the time was right to post.
I have an iOS application that was developed using Xcode 3.2 and SDK 4.2. When I built the bundle, I targeted iOS 3, so that people running older iPhones (like my wife who has iPhone 3 with iOS 3.x on it) can run the application. The app was also tested on, and runs fine with, the latest 4.x iOS.
With the release of iOS 5, I want to make sure my app is compatible. There is nothing new in iOS 5 that my app uses. I have installed the latest version of Xcode and iOS SDK. My question is this : if I rebuild my app using this new Xcode/SDK combination, and set the target iOS level to something older than 5, for backwards compatibility, this still means that my application is built for, and is thus compatible with, iOS5, correct? I will of course test it with iOS 5, but I want to be able to claim it's supported on iOS5, while still maintaining backwards compatibility.
Do I understand correctly how this works?
Thanks!
Mark
回答1:
Yes, that's no problem. You should always build with the latest SDK but if you set your Deployment Target to, let's say, 4.2 (which is common for many apps), or even 3.0, as you intend to do, of course it will run under iOS 5.
Testing it will still be wise since there are some changes that might lead to bugs in iOS 5, but in general, it shouldn't be a problem.
来源：https://stackoverflow.com/questions/7841225/target-ios-level-with-xcode-for-backward-compatability