问题
I want to change my iOS SDK. I have ios 5 and xcode 4.2 but I have to decrease it to iOS 4.2 SDK because of my application. In developer.apple.com the xcode 4.1 with iOS 5 so it is not available. How can I find xcode 4.1 with ios sdk 4.2 or how can I setup the ios sdk 4.2 without download xcode again. If it is not possible can you give me a linq for download xcode 4.1 with ios sdk 4.2
回答1:
The base SDK should be the currently available one - it's the version of the SDK that you have installed to compile against.
However, further down the settings list you'll see that you can set the "Deployment Target" to be for lower versions iOS. That's the one that specifies the lower version of the OS that you app will run on.
回答2:
Latest SDK included all required features from previous SDK versions. You shouldn't worry about it. If you want to support previous versions of iOS just set iOS Deployment Target to iOS 4.2 (or another would you like) in project settings at Build Settings tab.
来源：https://stackoverflow.com/questions/8338957/how-can-i-change-ios-sdk