How To Make iPhone App compatible with multiple SDK (firmware) versions
问题 With iOS4 coming out soon, I have already planned to include an iAd in a future update of an app of mine. I assume that this will make my app unusable for anyone on a firmware lower than 4.0. Is there a way to change that variables and the .xib file based on the user\'s firmware? Cheers. 回答1: Yes, you can build with the latest SDK (ie: 5.1) and still run on devices with earlier versions of the firmware (SDK). Set your Deployment Target to the earliest version you want to be able to run with,