问题
My app is currently built and running for iOS 5.1, using Xcode 5.1.1. For its first release, I would like to ship it only for iOS 7. Later on, in future releases, I would like to restore it the Deployment Target to iOS 6 or 5.
What are the implications of changing the Deployment Target? Apple's project settings are so nightmarishly complex that I'm afraid changing the Deployment Target will have a bunch of unknown side-effects in the project and compiler settings that I'll never be able to undo.
Is Project > General > Deployment Info > Deployment Target the correct place to raise and lower my "minimum OS required" setting?
回答1:
Yes you can do that but here's the implications of it.
Some of your currents users maybe on iOS5 & iOS6. I am assuming that's why you are supporting your current app for iOS 5.1. Now when you do your next release and increase the deployment target to iOS7 then only users running iOS7 will see an "update app" button & your new features. Old ones wouldn't have a clue. Lets say iOS6 users delete your app and try in install it again from App Store they won't be able to. What in a sense you did was loose some of your old iOS user base.
I feel like what you are trying to do is that you have some cool features you want to add to your app now and you know it works only in iOS 7. Afterward you will take your time to back port those features for iOS 5&6 users. Can it be done? Yes but its better to finish up your coding for older iOS support and then release your app.
Just my two cents.
By the way there are no "bunch of unknown side-effects that I'll never be able to undo".
来源：https://stackoverflow.com/questions/24092866/can-i-raise-my-ios-apps-deployment-target-to-a-more-recent-os-now-and-later-o