Book Image

Xamarin 4.x Cross-Platform Application Development - Third Edition

By : Jonathan Peppers
Book Image

Xamarin 4.x Cross-Platform Application Development - Third Edition

By: Jonathan Peppers

Overview of this book

Xamarin is a leading cross-platform application development tool used by top companies such as Coca-Cola, Honeywell, and Alaska Airlines to build apps. Version 4 features significant updates to the platform including the release of Xamarin.Forms 2.0 and improvements have been made to the iOS and Android designers. Xamarin was acquired by Microsoft so it is now a part of the Visual Studio family. This book will show you how to build applications for iOS, Android, and Windows. You will be walked through the process of creating an application that comes complete with a back-end web service and native features such as GPS location, camera, push notifications, and other core features. Additionally, you’ll learn how to use external libraries with Xamarin and Xamarin.Forms to create user interfaces. This book also provides instructions for Visual Studio and Windows. This edition has been updated with new screenshots and detailed steps to provide you with a holistic overview of the new features in Xamarin 4.
Table of Contents (19 chapters)
Xamarin 4.x Cross-Platform Application Development - Third Edition
About the Author
About the Reviewer
Customer Feedback

Using data-binding and MVVM

At this point, you should be grasping the basics of Xamarin.Forms, but are wondering how the MVVM design pattern fits into the picture. The MVVM design pattern was originally conceived for use along with XAML and the powerful data binding features XAML provides, so it is only natural that it is a perfect design pattern to be used with Xamarin.Forms.

Let's cover the basics of how data-binding and MVVM is set up with Xamarin.Forms:

  1. Your Model and ViewModel layers will remain mostly unchanged from the MVVM pattern we covered earlier in the book.

  2. Your ViewModels should implement the INotifyPropertyChanged interface, which facilitates data binding. To simplify things in Xamarin.Forms, you can use the BindableObject base class and call OnPropertyChanged when values change on your ViewModels.

  3. Any Page or control in Xamarin.Forms has a BindingContext, which is the object that it is data-bound to. In general, you can set a corresponding ViewModel to each view's BindingContext...