Supporting Multitasking on the iPhone

A 92-minute on-demand video course from the O’Reilly iPhone development series, covering how to add multitasking support to iPhone apps when Apple first introduced it in iOS 4. Topics include the app lifecycle states (background, suspended, terminated), the various background execution modes (audio, location, VoIP, finite-length tasks), state restoration, and the design patterns for apps that need to keep working when the user switches away.

Recorded in late 2010, just months after iOS 4 shipped and developers had to figure out how to retrofit apps written for the single-app iPhone OS world. The frameworks and patterns covered are still the foundation of iOS background execution today, though the modern guidance around battery and privacy has tightened considerably since.

Part of a four-course iPhone development series released October–November 2010 alongside Optimizing Tables, Consuming Web Services, and Injecting iAds.