mavencode01 / iOS-Background-Drawing-with-GCD

Summary: This app shows how to use Grand Central Dispatch (GCD) to do custom drawing in a background thread. This is helpful when the custom drawing is processor intensive and is causing the UI thread to become non-responsive. BackgroundUIView is the base class that provides the GCD functionality. The BackgroundUIView subclasses should override drawWithContext: and do the custom drawing there. The app supports multiple orientations and updates after orientation changes. The app is universal so it supports the ipad and iphone. For this example the user is presented with two options: draw in the background or on the main UI thread. The back button will remain responsive if the user picks the background option.