Book Image

Mastering Xamarin UI Development - Second Edition

By : Steven F. Daniel
Book Image

Mastering Xamarin UI Development - Second Edition

By: Steven F. Daniel

Overview of this book

This book will provide you with the knowledge and practical skills that are required to develop real-world Xamarin and Xamarin.Forms applications. You’ll learn how to create native Android app that will interact with the device camera and photo gallery, and then create a native iOS sliding tiles game. You will learn how to implement complex UI layouts and create customizable control elements based on the platform, using XAML and C# 7 code to interact with control elements within your XAML ContentPages. You’ll learn how to add location-based features by to your apps by creating a LocationService class and using the Xam.Plugin.Geolocator cross-platform library, that will be used to obtain the current device location. Next, you’ll learn how to work with and implement animations and visual effects within your UI using the PlatformEffects API, using C# code. At the end of this book, you’ll learn how to integrate Microsoft Azure App Services and use the Twitter APIs within your app. You will work with the Razor Templating Engine to build a book library HTML5 solution that will use a SQLite.net library to store, update, retrieve, and delete information within a local SQLite database. Finally, you will learn how to write unit tests using the NUnit and UITest frameworks.
Table of Contents (15 chapters)

Updating the WalkDistancePageViewModel using C#

Now that we have updated our WalkEntryPageViewModel ViewModel so that it can communicate with our LocationService class to obtain the current GPS Latitude and Longitude coordinates of the device, we can now proceed to start updating the WalkDistancePageViewModel class. We are doing this so that it can use our location service to obtain the current GPS device location, as well as handle checking for changes in GPS location in the background and raising an EventHandler containing the updated coordinates that we can reference within our WalkDistancePage.xaml.cs code-behind file.

Let's take a look at how we can achieve this by following these steps:

  1. Ensure that the WalkDistancePageViewModel.cs file is displayed within the code editor and enter the following highlighted code sections within the code snippet:
      //
// WalkDistancePagePageViewModel...