iOS8/Swift Data Persistence after uninstall

Question

I'm developing an iPhone application for iOS8 in Swift. I currently save all the user data through NSUserDefaults and this works completely fine. Once I uninstall the demo app from my phone and reinstall it through XCode6, all the NSUserDefaults are gone, this is expected.

Question: How do I persist user data after uninstall?

Answer 1

将数据存储在钥匙串中，钥匙串数据将持续存在。