XCode 4.2.1 (iOS SDK 5.0) for Lion XCode 4.2.1 (iOS SDK 5.0) for Lion, 下载需要开发者帐号https://developer.apple.com/downloads/download.action?path=Developer_Tools/xcode_4.2.1_for_lion/xcode_4.2.1_for_lion.dmg 敦品厚德 格物致知