IOS3 Compatible App in IOS4 Mutlitasking

Question

This is a follow on from IPhone App Submission Issues

If I have a IOS3 compatible app, how does it handle in IOS4 in regards to Multitasking? i.e. When the IOS3 app

Answer 1

If you compile an app using the 4.x SDK but with a deployment target of 3.x, then when running under iOS 4.0, suspend (applicationDidEnterBackground) and sometimes resume (applicationWillEnterForeground:) will be called, depending on what the user or the system did in the meantime; and under iPhone OS 3.x, terminate (applicationWillTerminate ) will be called and your app will be terminated.

See the iOS App Programming Guide for more details.