In addition to providing the core building blocks for the MVVM pattern, Xamarin.Forms also includes a very basic service that handles dependency registration and resolution, called the DependencyService. We actually used this service in the previous chapter to register and resolve our custom navigation service. Like many of the services and components built into the Xamarin.Forms toolkit, DependencyService is designed to help get developers up and running quickly by providing an easy-to-use basic implementation. It is in no way the only way of handling dependencies in a Xamarin.Forms mobile app and, in most complex apps, you will quickly outgrow the capabilities of the Xamarin.Forms DependencyService. For example, the Xamarin.Forms DependencyService doesn't provide a way of doing constructor injection.
There...