Book Image

Xamarin Mobile Development for Android Cookbook

By : Matthew Leibowitz
Book Image

Xamarin Mobile Development for Android Cookbook

By: Matthew Leibowitz

Overview of this book

Xamarin is used by developers to write native iOS, Android, and Windows apps with native user interfaces and share code across multiple platforms not just on mobile devices, but on Windows, Mac OS X, and Linux. Developing apps with Xamarin.Android allows you to use and re-use your code and your skills on different platforms, making you more productive in any development. Although it’s not a write-once-run-anywhere framework, Xamarin provides native platform integration and optimizations. There is no middleware; Xamarin.Android talks directly to the system, taking your C# and F# code directly to the low levels. This book will provide you with the necessary knowledge and skills to be part of the mobile development era using C#. Covering a wide range of recipes such as creating a simple application and using device features effectively, it will be your companion to the complete application development cycle. Starting with installing the necessary tools, you will be guided on everything you need to develop an application ready to be deployed. You will learn the best practices for interacting with the device hardware, such as GPS, NFC, and Bluetooth. Furthermore, you will be able to manage multimedia resources such as photos and videos captured with the device camera, and so much more! By the end of this book, you will be able to create Android apps as a result of learning and implementing pro-level practices, techniques, and solutions. This book will ascertain a seamless and successful app building experience.
Table of Contents (20 chapters)
Xamarin Mobile Development for Android Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Detecting device shakes


A fairly common gesture that can be implemented using sensors is the shake gesture. This can be used to shuffle cards in a game or tracks in a playlist.

How to do it...

To detect a shake, we will need to record the data from the accelerometer and determine whether a shake has occurred:

  1. First, we implement the ISensorEventListener interface, and register it with the manager:

    var manager = SensorManager.FromContext(this);
    var type = SensorType.Accelerometer;
    var accelerometer = manager.GetDefaultSensor(type);
    manager.RegisterListener(
      this, accelerometer, SensorDelay.Fastest);
  2. Then, we will need a few fields that will store the values across the accelerometer events:

    private int lastUpdate;
    private float lastX;
    private float lastY;
    private float lastZ;
  3. As we are also going to process shakes, we will need a field to hold the shake related data:

    private int lastShake;
  4. In the OnSensorChanged() method, we ensure that we only process the events after a reasonable interval of time...