Book Image

Android Studio 4.0 Development Essentials - Java Edition

By : Neil Smyth
Book Image

Android Studio 4.0 Development Essentials - Java Edition

By: Neil Smyth

Overview of this book

Android rolls out frequent updates to meet the demands of the dynamic mobile market and to enable its developer community to lead advancements in application development. This book focuses on the updated features of Android Studio (the fully integrated development environment launched by Google) to build reliable Android applications using Java. The book starts by outlining the steps necessary to set up an Android development and testing environment. You’ll then learn how to create user interfaces with the help of Android Studio Layout Editor, XML files, and by writing the code in Java. The book introduces you to Android architecture components and advanced topics such as intents, touchscreen handling, gesture recognition, multi-window support integration, and biometric authentication, and lets you explore key features of Android Studio 4.0, including the layout editor, direct reply notifications, and dynamic delivery. You’ll also cover Android Jetpack in detail and create a sample app project using the ViewModel component. Finally, you’ll upload your app to the Google Play Console and handle the build process with Gradle. By the end of this book, you’ll have gained the skills necessary to develop applications using Android Studio 4.0 and Java.
Table of Contents (88 chapters)
88
Index

74.4 Requesting Permission at Runtime

A permission request is made via a call to the requestPermissions() method of the ActivityCompat class. When this method is called, the permission request is handled asynchronously and a method named onRequestPermissionsResult() is called when the task is completed.

The requestPermissions() method takes as arguments a reference to the current activity, together with the identifier of the permission being requested and a request code. The request code can be any integer value and will be used to identify which request has triggered the call to the onRequestPermissionsResult() method. Modify the MainActivity.java file to declare a request code and request recording permission in the event that the permission check failed:

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import androidx.core.app.ActivityCompat;

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public class MainActivity extends AppCompatActivity {

 

    private static String TAG = "PermissionDemo";

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