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

61.4 Designing the User Interface Layout for ActivityB

The elements that are required for the user interface of the second activity are a Plain Text EditText, TextView and Button view. With these requirements in mind, load the activity_b.xml layout into the Layout Editor tool, and add the views.

During the design process, note that the onClick property on the button view has been configured to call a method named answerQuestion, and the TextView and EditText views have been assigned IDs textView1 and editText1 respectively. Once completed, the layout should resemble that illustrated in Figure 61-4. Note that the text on the button (which reads “Answer Question”) has been extracted to a string resource named answer_question.

With the layout complete, click on the Infer constraints toolbar button to add the necessary constraints to the layout:

Figure 61-4