Beginning Android Programming with Android Studio, Fourth Edition

Chapter 12Developing Android Services

WHAT YOU WILL LEARN IN THIS CHAPTER

• How to create a service that runs in the background
• How to perform long-running tasks in a separate thread
• How to perform repeated tasks in a service
• How an activity and a service communicate

CODE DOWNLOAD

The wrox.com code downloads for this chapter are found at www.wrox.com/go/beginningandroidprog on the Download Code tab. The code is in the Chapter 12 download and individually named according to the names throughout the chapter.

A service is an application in Android that runs in the background without needing to interact with the user. For example, while using an application, you might want to play some background music at the same time. In this case, the code that is playing the background music has no need to interact with the user; therefore, it can be run as a service. Also, services are ideal for situations in which there is no need to present a user interface (UI) to the user. A good example of this scenario is an application that continually logs the geographical coordinates of the device. In this case, you can write a service to do that in the background. In this chapter, you find out how to create your own services and use them to perform background tasks asynchronously.

CREATING YOUR OWN SERVICES

The best way to understand how a service works is by creating one. The following Try It Out shows you the steps to create a simple service. Subsequent sections add more functionality ...