I have a music player app which implements background audio. I’m trying to update the screenshot in the iOS7 multi-tasking switcher when the track changes. So, if I background the app during Song A, it finishes and Song B comes on, if I then go into the tray I’d like to see a screenshot showing Song B’s artwork, title, etc.
I’ve done some digging and not managed to find any way to tell iOS to update short of implementing Background Fetch and going all out with that. Is there another means of doing this, something I can call to tell it to refresh it when my tracks change?
Apple does not provide any means of doing this. Even iOS own media player does not have this ability.
来源：https://stackoverflow.com/questions/20967916/programmatically-refresh-screenshot-in-ios7-multitasking-screen