Book Image

Android Studio 4.0 Development Essentials - Kotlin Edition

By : Neil Smyth
Book Image

Android Studio 4.0 Development Essentials - Kotlin Edition

By: Neil Smyth

Overview of this book

Kotlin as an Android-compatible programming language is becoming increasingly popular. Fully updated for Android Studio 4.0, this book will teach you the skills necessary to develop Android-based applications using Kotlin. Starting with the basics, this book outlines the steps necessary to set up Android development and testing environments, and goes on to introduce you to programming in Kotlin. You’ll practice Java to Kotlin code conversion and explore data types, operators, expressions, loops, functions, as well as the basics of OOP in Kotlin. You’ll then learn about Android architecture components and advanced topics, such as intents, touchscreen handling, gesture recognition, multi-window support integration, and biometric authentication. As you make progress, you’ll explore Android Studio 4.0’s key features, including layout editor, direct reply notifications, and dynamic delivery. You’ll also delve into Android Jetpack and create a sample app project using ViewModel, the Android Jetpack component. Finally, you will upload your app to Google Play Console and model the build process using Gradle. By the end of this Android book, you’ll be fully prepared to develop applications using Android Studio 4.0 and Kotlin.
Table of Contents (97 chapters)
97
Index

32.3 Using Apply Changes

When a project has been loaded into Android Studio, but is not yet running on a device or emulator, it can be launched as usual using either the run (marked A in Figure 32-1) or debug (B) button located in the toolbar:

Figure 32-1

After the app has launched and is running, the icon on the run button will change to indicate that the app is running and the Apply Changes and Restart Activity and Apply Code Changes buttons will be enabled as indicated in Figure 32-2 below:

Figure 32-2

If the changes are unable to be applied when one of the Apply Changes buttons is selected, Android Studio will display a message indicating the failure together with an explanation. Figure 32-3, for example, shows the message displayed by Android Studio when the Apply Code Changes option is selected after a change has been made to a resource file:

Figure 32-3

In this situation, the solution is to use the Apply Changes and Restart Activity option (for...