Book Image

Android Studio 3.5 Development Essentials - Java Edition

By : Neil Smyth
Book Image

Android Studio 3.5 Development Essentials - Java Edition

By: Neil Smyth

Overview of this book

Android applications have become an important part of our daily lives and lots of effort goes into developing an Android application. This book will help you to build you own Android applications using Java. Android Studio 3.5 Development Essentials – Java 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 emulator. You will test apps on physical Android devices, then study Android Studio code editor and constraint layout, Android architecture, the anatomy of an Android app, and Android activity state changes. The book then covers advanced topics such as views and widgets implementation, multi-window support integration, and biometric authentication, and finally, you will learn to upload your app to 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 Java.
Table of Contents (86 chapters)
86
Index

81.9 Adding the CancellationSignal

Once initiated, the biometric authentication process is performed independently of the app. To provide the app with a way to cancel the operation, an instance of the CancellationSignal class is created and passed to the biometric authentication process. This CancellationSignal instance can then be used to cancel the process if necessary. The cancellation signal instance may be configured with a listener which will be called when the cancellation is completed. Add a new method to the activity class to configure and return a CancellationSignal object as follows:

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import android.os.CancellationSignal;

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   private CancellationSignal cancellationSignal;

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    private CancellationSignal getCancellationSignal() {

 

        cancellationSignal = new CancellationSignal();

        cancellationSignal...