Book Image

Android Studio 3.5 Development Essentials - Kotlin Edition

By : Neil Smyth
Book Image

Android Studio 3.5 Development Essentials - Kotlin Edition

By: Neil Smyth

Overview of this book

Popularity of Kotlin as an Android-compatible language keeps growing every day. This book will help you to build your own Android applications using Kotlin. Android Studio 3.5 Development Essentials Kotlin Edition first teaches you to install Android development and test environment on different operating systems. Next, you will create an Android app and a virtual device in Android studio, and install an Android application on emulators. You will test apps on physical android devices, then study Android Studio code editor, Android architecture, and the anatomy of an Android app. The focus then shifts to Kotlin language. You’ll get an overview of Kotlin language and practice converting code from Java to Kotlin. You’ll also explore Kotlin data types, operators, expressions, loops, functions, and the basics of OOP concept in Kotlin. This book will then cover Android Jetpack and how to create an example app project using ViewModel component, as well as advanced topics such as views and widgets implementation, multi-window support integration, and biometric authentication. Finally, you will learn to upload your app to the Google Play Console and handle the build process with Gradle. By the end of this book, you will have gained enough knowledge to develop powerful Android applications using Kotlin.
Table of Contents (93 chapters)
93
Index

31.6 Using Apply Code Changes

Begin by clicking on the run button and selecting a suitable emulator or physical device as the run target. After clicking the run button, track the amount of time before the example app appears on the device or emulator.

Once running, click on the action button (the button displaying an envelope icon located in the lower right-hand corner of the screen). Note that a Snackbar instance appears displaying text which reads “Replace with your own action” as shown in Figure 31-6:

Figure 31-6

Once the app is running, the Apply Changes buttons should have been enabled indicating that certain project changes can be applied without having to reinstall and restart the app. To see this in action, edit the MainActivity.kt file, locate the onCreate method and modify the action code so that a different message is displayed when the action button is selected:

fab.setOnClickListener { view ->

    Snackbar.make(view...