What to do if I need to support ios4 muititask when build an app?

Question

I am developing an app, it gets a list of locations from internet, and will trigger map app when click one item of the table list.

I found when I try to go back from map app (double tap or just one tap of the home key), my app just restart to the first screen.

I know ios4 have multitask feature, my app is built with SDK3 and test in my new ipod4. What can I do if I want to user see the last screen that he left when he came back.

Answer 1

You would need to build with iOS 4 (NOT 3) and you will automatically have fast switching enabled.

But fast switching only works on iOS 4.

Answer 2

You should set your build SDK to the most current. You can still support your app for users with older OS's by setting the apps deployment target. See here for some tips, tricks and common setups.