Book Image

Asynchronous Android

By : Steve Liles
Book Image

Asynchronous Android

By: Steve Liles

Overview of this book

With more than a million apps available from Google Play, it is more important than ever to build apps that stand out from the crowd. To be successful, apps must react quickly to user input, deliver results in a flash, and sync data in the background. The key to this is understanding the right way to implement asynchronous operations that work with the platform, instead of against it. Asynchronous Android is a practical book that guides you through the concurrency constructs provided by the Android platform, illustrating the applications, benefits, and pitfalls of each.Learn to use AsyncTask correctly to perform operations in the background, keeping user-interfaces running smoothly while avoiding treacherous memory leaks. Discover Handler, HandlerThread and Looper, the related and fundamental building blocks of asynchronous programming in Android. Escape from the constraints of the Activity lifecycle to load and cache data efficiently across your entire application with the Loader framework. Keep your data fresh with scheduled tasks, and understand how Services let your application continue to run in the background, even when the user is busy with something else.Asynchronous Android will help you to build well-behaved apps with smooth, responsive user-interfaces that delight users with speedy results and data that's always fresh, and keep the system happy and the battery charged by playing by the rules.
Table of Contents (14 chapters)
Asynchronous Android
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Introducing Service and IntentService


If the basic unit of a visible application is Activity, its equivalent unit for non-visible components is Service. Just like activities, services must be declared in the AndroidManifest file so that the system is aware of them and can manage them for us.

<service android:name=".MyService"/>

Service has lifecycle callback methods similar to those of Activity, which are always invoked on the application's main thread.

Also, just like Activity, Service does not automatically entail a separate background thread or process, and performing intensive or blocking operations in a Service callback method can lead to an Application Not Responding dialog.

However, there are several ways in which services are different to activities, listed as follows:

  • A Service does not provide a user interface

  • There can be many services active at the same time within an application

  • A Service can remain active even if the application hosting it is not the current foreground application...