Want to do MVVM without the frameworks? Xamarin Forms provides everything we need to implement the pattern and make our ViewModels testable.
Note that some naming, patterns and code have been borrowed from the excellent FreshMVVM framework. This is a great lightweight framework to get started with if you don’t want to roll your own.
Simply put, MVVM helps us to abstract any UI logic out of the View and into a ViewModel to make it testable, while the data and business logic remains in the Model.
To avoid boilerplate code we’re going to create a couple of base classes, one for our Views, and one for our ViewModels.