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

Wiring up the UI with the Java code (part 1)


To achieve an interactive app, we will do three things:

  1. We will call setContentView from the onCreate method to show the progress of our UI when we run the app

  2. We will write two more methods of our own, and each one will call setContentView on a different layout (that we have yet to design)

  3. Then, later in this chapter, when we design two more UI layouts, we will be able to load them at the click of a button

As we will be building a ConstraintLayout and a TableLayout, we will call our new methods loadConstraintLayout and loadTableLayout, respectively.

Let's do that now, and then we can see how we can add some buttons that call these methods alongside some neatly formatted text.

Inside the onCreate method, add the following highlighted code:

@Override
protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);

   setContentView(R.layout.main_menu);
}

The code uses the setContentView method to load the UI we are currently...