The speed and efficiency of a long-running, data-intensive operation often improves when you split it into smaller operations running on multiple threads. On a device that has a CPU with multiple processors (cores), the system can run the threads in parallel, rather than making each sub-operation wait for a chance to run. For example, decoding multiple image files in order to display them on a thumbnail screen runs substantially faster when you do each decode on a separate thread.

　　This class shows you how to set up and use multiple threads in an Android app, using a thread pool object. You'll also learn how to define code to run on a thread and how to communicate between one of these threads and the UI thread.

4.Lessons

4.1 Specifying the Code to Run on a Thread

Learn how to write code to run on a separate Thread, by defining a class that implements theRunnable interface.

4.2 Creating a Manager for Multiple Threads

Learn how to create an object that manages a pool of Thread objects and a queue of Runnableobjects. This object is called a ThreadPoolExecutor.

4.3 Running Code on a Thread Pool Thread

Learn how to run a Runnable on a thread from the thread pool.

4.4 Communicating with the UI Thread

Learn how to communicate from a thread in the thread pool to the UI thread.