Book Image

Android Studio 4.1 Development Essentials – Kotlin Edition

By : Neil Smyth
Book Image

Android Studio 4.1 Development Essentials – Kotlin Edition

By: Neil Smyth

Overview of this book

Android 11 has a ton of new capabilities. It comes up with three foci: a people-centric approach to communication, controls to let users quickly access and manage all of their smart devices, and privacy to give users more ways to control how data on devices is shared. This book starts off with the steps necessary to set up an Android development and testing environment, followed by an introduction to programming in Kotlin. An overview of Android Studio and its architecture is provided, followed by an in-depth look at the design of Android applications and user interfaces using the Android Studio environment. You will also learn about the Android architecture components along with some advanced topics such as touch screen handling, gesture recognition, the recording and playback of audio, app links, dynamic delivery, the AndroidStudio profiler, Gradle build configuration, and submitting apps to the Google Play Developer Console. The concepts of material design are also covered in detail. This edition of the book also covers printing, transitions, and cloud-based file storage; foldable device support is the cherry on the cake. By the end of this course, you will be able to develop Android 11 Apps using Android Studio 4.1, Kotlin, and Android Jetpack. The code files for the book can be found here: https://www.ebookfrenzy.com/retail/as41kotlin/index.php
Table of Contents (95 chapters)
95
Index

74.5 The Room Database

The Room database class is created by extending the RoomDatabase class and acts as a layer on top of the actual SQLite database embedded into the Android operating system. The class is responsible for creating and returning a new room database instance and for providing access to the DAO instances associated with the database.

The Room persistence library provides a database builder for creating database instances. Each Android app should only have one room database instance, so it is best to implement defensive code within the class to prevent more than one instance being created.

An example Room Database implementation for use with the example customer table is outlined in the following code listing:

import android.content.Context

import android.arch.persistence.room.Database

import android.arch.persistence.room.Room

import android.arch.persistence.room.RoomDatabase

 

@Database(entities = [(Customer::class)], version = 1)

abstract...