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

92.11 Testing the Project

With the project now complete, run the app on a physical Android device or emulator session and click on the Authenticate button to display the BiometricPrompt dialog as shown in Figure 92-3:

Figure 92-3

Once running, either touch the fingerprint sensor or use the extended controls panel within the emulator to simulate a fingerprint touch as outlined in the chapter entitled “Using and Configuring the Android Studio AVD Emulator”. Assuming a registered fingerprint is detected the prompt dialog will return to the main activity where the toast message from the successful authentication callback method will appear.

Click the Authenticate button once again, this time using an unregistered fingerprint to attempt the authentication. This time the biometric prompt dialog will indicate that the fingerprint was not recognized:

Figure 92-4

Verify that the error handling callback is working by clicking on the activity outside of the...