Book Image

Android Programming for Beginners

By : John Horton, Paresh Mayani
Book Image

Android Programming for Beginners

By: John Horton, Paresh Mayani

Overview of this book

Android is the most popular OS in the world. There are millions of devices accessing tens of thousands of applications. It is many people's entry point into the world of technology; it is an operating system for everyone. Despite this, the entry-fee to actually make Android applications is usually a computer science degree, or five years’ worth of Java experience. Android Programming for Beginners will be your companion to create Android applications from scratch—whether you’re looking to start your programming career, make an application for work, be reintroduced to mobile development, or are just looking to program for fun. We will introduce you to all the fundamental concepts of programming in an Android context, from the Java basics to working with the Android API. All examples 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, make location-aware apps with Google Maps integration, and store your user’s data with SQLite. In addition, you’ll see how to make your apps multilingual, capture images from a device’s camera, 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 (37 chapters)
Android Programming for Beginners
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

The Android SQLite API


There are a number of different ways in which the Android API makes it fairly easy for us to use our app's database. The first class we need to get familiar with is SQLiteOpenHelper.

SQLiteOpenHelper and SQLiteDatabase

The SQLiteDatabase class is the class that represents the actual database. The SQLiteOpenHelper class, however, is where most of the action takes place. This class will enable us to get access to a database and initialize an instance of SQLiteDatabase.

In addition, the SQLiteOpenHelper class, which we will extend in our forthcoming mini app, has two methods to override. First, it has an onCreate method, which is called the first time a database is used, and therefore it makes sense that we place our SQL in this method to create our table structure.

The other method we must override is onUpgrade, which, as you can probably guess, is called when we upgrade our database (ALTER its structure). Exactly how this works is best explained with a practical example...