检查 iPhone 应用程序中使用的 SDK 方法

Question

As Apple adds new APIs and new methods to APIs with every new iOS update or release and given that nowadays you can't even test on an iOS 3.x simulator, is there any way to test your iPhone app in older SDKs or to know what SDK level you are using through it?

Downgrading to an old Xcode with a 3.x simulator is not an option and, well, there are tons of methods introduced in, say, 4.2.

Has any one come up with a lib, script, tool, anything, that analyzes the code to show API usage?

Answer 1

The way most iOS developers do this is to keep around an old 1st or 2nd generation iPod Touch (or other old iPhone device) that hasn't been updated past the oldest iPhone OS version that they plan on supporting with their Deployment Target setting.

A cheap used iOS device, even with a scratched/cracked display or mostly dead battery, from eBay (et.al. or some neighbor or nephew who upgraded), might work.

Testing on an old device is actually a better and more accurate check than just testing with the Simulator, as the Simulator for various SDK versions supported APIs that the device at that OS level did not.