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

81.7 Checking the Security Settings

Earlier in this chapter steps were taken to configure the lock screen and register fingerprints on the device or emulator on which the app is going to be tested. It is important, however, to include defensive code in the app to make sure that these requirements have been met before attempting to seek fingerprint authentication. These steps will be performed within the onCreate method residing in the MainActivity.java file, making use of the Keyguard and PackageManager manager services. Note that code has also been added to verify that the USE_BIOMETRIC permission has been configured for the app:

package com.ebookfrenzy.biometricdemo;

 

import androidx.appcompat.app.AppCompatActivity;

import androidx.core.app.ActivityCompat;

 

import android.widget.Toast;

import android.Manifest;

import android.content.pm.PackageManager;

 

import android.app.KeyguardManager;

 

public class MainActivity extends...