Taking screenshot from background app programmatically in iOS 8 using private api but on device "no jailbreak"

Is there a way to take a screenshot while the app is in the background. I saw questions

Releasing IOSurface

Taking screenshots in the background (iOS) - Improving performance

And I couldn't figure out if these answers were for a jailbreak device, nor where did they get the IOSurface structure from. I tried to implement the code and couldn't do it. So my question is that. Is it possible to take a screenshot while the app is in the background in iOS 8 using a private framework, but it should be possible to run on invulnerable devices. If it can help anyone.