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

Device detection mini-app


The best way to learn about detecting and responding to devices and their varying attributes (screens, orientations, and so on) is to make a simple app:

  1. Create a new Basic Activity project and call it Device Detection. Leave all the other settings at their defaults.

  2. Open the activity_main.xml file in the design tab and delete the default Hello world! TextView.

  3. Drag a Button onto the top of the screen and set its onClick property to detectDevice. We will code this method in a minute.

  4. Drag two TextView widgets onto the layout, one below the other, and set their id properties to txtOrientation and txtResolution respectively.

  5. Check you have a layout that looks something like the following screenshot:

    Note

    I have stretched my widgets (mainly horizontally) and increased the textSize attributes to 24sp to make them clearer on the screen, but this is not required for the app to work correctly.

  6. Click the Infer Constraints button to secure the positions of the UI elements.

Now we...