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

52.2 Designing the User Interface Layout for MainActivity

The user interface for MainActivity will consist of a ConstraintLayout view containing EditText (Plain Text), TextView and Button views named editText1, textView1 and button1 respectively. Using the Project tool window, locate the activity_main.xml resource file for MainActivity (located under app -> res -> layout) and double-click on it to load it into the Android Studio Layout Editor tool. Select and delete the default “Hello World!” TextView.

Drag a TextView widget from the palette and drop it so that it is centered within the layout and use the Attributes tool window to assign an ID of textView1.

Drag a Button object from the palette and position it so that it is centered horizontally and located beneath the bottom edge of the TextView. Change the text property so that it reads “Ask Question” and configure the onClick property to call a method named askQuestion.

Next, add a Plain...