Book Image

Android 9 Development Cookbook - Third Edition

By : Rick Boyer
Book Image

Android 9 Development Cookbook - Third Edition

By: Rick Boyer

Overview of this book

The Android OS has the largest installation base of any operating system in the world. There has never been a better time to learn Android development to write your own applications, or to make your own contributions to the open source community! With this extensively updated cookbook, you'll find solutions for working with the user interfaces, multitouch gestures, location awareness, web services, and device features such as the phone, camera, and accelerometer. You also get useful steps on packaging your app for the Android Market. Each recipe provides a clear solution and sample code you can use in your project from the outset. Whether you are writing your first app or your hundredth, this is a book that you will come back to time and time again, with its many tips and tricks on the rich features of Android Pie.
Table of Contents (24 chapters)
Title Page
Copyright and Credits
Dedication
About Packt
Contributors
Preface
Index

Inserting a widget into a layout


As you may have seen from previous recipes, widgets are declared in a layout file, or created in code. For this recipe, we will go step by step to add a button with the Android Studio Designer. (For later recipes, we will just show the layout XML.) After creating the button, we will create a method to receive the button click events using onClickListener().

Getting ready

Start a new project in Android Studio and call it InsertWidget. Use the default options for creating a Phone and Tablet project and select Empty Activity when prompted for the Activity Type. You can delete the default TextView (or leave it) as it will not be needed for this recipe.

How to do it...

To insert a widget into a layout, follow these steps:

  1. Open the activity_main.xml file in Android Studio and click on the Design tab. As you can see, by default, Android Studio adds a TextView to the layout. Select the TextView and delete it:

  1. Find Button in the widget list and drag it to the center of...