Book Image

Android Programming for Beginners - Second Edition

By : John Horton
Book Image

Android Programming for Beginners - Second Edition

By: John Horton

Overview of this book

Are you trying to start a career in programming, but haven't found the right way in? Do you have a great idea for an app, but don't know how to make it a reality? Or maybe you're just frustrated that in order to learn Android, you must know Java. If so, then this book is for you. This new and expanded second edition of Android Programming for Beginners will be your companion to create Android Pie applications from scratch. We will introduce you to all the fundamental concepts of programming in an Android context, from the basics of Java to working with the Android API. All examples use the up-to-date API classes, and are created from within Android Studio, the official Android development environment that helps supercharge your application development process. After this crash course, we'll dive deeper into Android programming and you'll learn how to create applications with a professional-standard UI through fragments and store your user's data with SQLite. In addition, you'll see how to make your apps multilingual, draw to the screen with a finger, and work with graphics, sound, and animations too. By the end of this book, you'll be ready to start building your own custom applications in Android and Java.
Table of Contents (35 chapters)
Android Programming for Beginners - Second Edition
Contributors
Preface
Other Books You May Enjoy
Index

Some other overridden methods


Almost certainly, you will have noticed that there are two other auto-generated methods in the code of all our projects using the Basic Activity template. They are onCreateOptionsMenu and onOptionsItemSelected. Most Android apps have a pop up menu, so Android Studio generates one by default, including the basic code to make it work.

You can see the XML that describes the menu in res/menu/menu_main.xml from the project explorer. The key line of XML code is this:

<item
      android:id="@+id/action_settings"
      android:orderInCategory="100"
      android:title="@string/action_settings"
      app:showAsAction="never" />

This describes a menu item with the text Settings. If you run any of the apps built with the Basic Activity template we have created so far, you can see the button as shown in the following screenshot:

If you tap the button, you can see it in action, as shown next:

So how do the onCreateOptionsMenu and onOptionsItemSelected methods produce...