small mvvm example example with unit tests

[hulluP]

Description the mvvm toolkit looks very promising and is straight foreward to apply for a basic app. Missing though is an example which shows the full potential of this in a scenario with tests. Specifically where

• services are registered temporary
• services are registered to a later point not in the start of the programm to allow multiple instances of the services to be used
• services are unregistered again also for testing

Steps to Reproduce I found the following issue which actually helped me to get some of the above working but now I am confused which is the correct way to use mvvm?

• according to https://learn.microsoft.com/en-us/dotnet/communitytoolkit/mvvm/ioc fetching a registered services works with App.Current.Services.GetService<ContactsViewModel>();
• when I need to register a service though to a later point I use Ioc.Default.ConfigureServices( new ServiceCollection() .AddSingleton<INavigationService>(new NavigationService(rootFrame)) .BuildServiceProvider()); explained very good in this issue and when I want to get the singelton instance I call Ioc.Default.GetRequiredService<INavigationService>().Navigate<SomePage>();
• how would I add a mock service for testing

big question now what is the right way to register services and get the instance.

Enviorement .net 7 ios and android