Continue task execution in background

Am I missing something here with Multitasking feature. I know we can execute a task in background, but what I really need is that task continues execution when app goes in background. So what I need is different than starting a new task in background. If images are being loaded in a view and user presses the home button to make the app go in background, I want that images continue to load and when user makes the app active again, he can see all the loaded images. How开发者_如何转开发 can this be done? Thanks a lot.

Documentation on background task execution is on Apple's site in the iPhone Application Programming Guide.

According to mentioned documentation, if you use beginBackgroundTaskWithExpirationHandler: while in foreground, it will keep executing in background until it ends. Once that task has ended, your application is eligible to be suspended.