Mastering Xamarin.Forms - Second Edition

Adding ViewModels

In most cases, Views (Pages) and ViewModels have a one-to-one relationship. However, it is possible for a View (Page) to contain multiple ViewModels or for a ViewModel to be used by multiple Views (Pages). For now, we will simply have a single ViewModel for each Page. Before we create our ViewModels, we will start by creating a base ViewModel class, which will be an abstract class containing the basic functionality that each of our ViewModels will inherit. Initially, the base ViewModel abstract class will only contain a couple of members and wilimplement INotifyPropertyChanged, but we will add to this class as we continue to build upon the TripLog app throughout this book.

In order to create a base ViewModel, perform the ...