Book Image

Android Studio 4.1 Development Essentials – Kotlin Edition

By : Neil Smyth
Book Image

Android Studio 4.1 Development Essentials – Kotlin Edition

By: Neil Smyth

Overview of this book

Android 11 has a ton of new capabilities. It comes up with three foci: a people-centric approach to communication, controls to let users quickly access and manage all of their smart devices, and privacy to give users more ways to control how data on devices is shared. This book starts off with the steps necessary to set up an Android development and testing environment, followed by an introduction to programming in Kotlin. An overview of Android Studio and its architecture is provided, followed by an in-depth look at the design of Android applications and user interfaces using the Android Studio environment. You will also learn about the Android architecture components along with some advanced topics such as touch screen handling, gesture recognition, the recording and playback of audio, app links, dynamic delivery, the AndroidStudio profiler, Gradle build configuration, and submitting apps to the Google Play Developer Console. The concepts of material design are also covered in detail. This edition of the book also covers printing, transitions, and cloud-based file storage; foldable device support is the cherry on the cake. By the end of this course, you will be able to develop Android 11 Apps using Android Studio 4.1, Kotlin, and Android Jetpack. The code files for the book can be found here: https://www.ebookfrenzy.com/retail/as41kotlin/index.php
Table of Contents (95 chapters)
95
Index

78.4 Declaring Request Codes

Working with files in the Storage Access Framework involves triggering a variety of intents depending on the specific action to be performed. Invariably this will result in the framework displaying the storage picker user interface so that the user can specify the storage location (such as a directory on Google Drive and the name of a file). When the work of the intent is complete, the application will be notified by a call to a method named onActivityResult().

Since all intents from a single activity will result in a call to the same onActivityResult() method, a mechanism is required to identify which intent triggered the call. This can be achieved by passing a request code through to the intent when it is launched. This code is then passed on to the onActivityResult() method by the intents, enabling the method to identify which action has been requested by the user. Before implementing the onClick handlers to create, save and open files, the first...