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

25.5 Designing the User Interface

The user interface layout for the MainActivity class in this example is to consist of a ConstraintLayout, a Button and a TextView as illustrated in Figure 25-1.

Figure 25-1

Locate and select the activity_main.xml file created by Android Studio (located in the Project tool window under app -> res -> layouts) and double-click on it to load it into the Layout Editor tool.

Make sure that Autoconnect is enabled, then drag a Button widget from the palette and move it so that it is positioned in the horizontal center of the layout and beneath the existing TextView widget. When correctly positioned, drop the widget into place so that appropriate constraints are added by the autoconnect system. Add any missing constraints by clicking on the Infer Constraints button in the layout editor toolbar.

With the Button widget selected, use the Attributes panel to set the text property to Press Me. Using the yellow warning button located in the...