DryIoc switch between fake and real service implementation (Xamarin Forms)VS2017

Question

I have a situation where I want to switch between "FakeService" and "RealService" at runtime.

MyViewModel

    public class BookingViewModel 
    {
        private readonly IBookingService bookingService;

        public WelcomePageViewModel(
            INavigationService navigationService,IBookingService bookingService)
        {
            this.bookingService= bookingService;
        }
     }

In my App.xaml I do as follows:

    private IContainer container;
    protected override void RegisterTypes(IContainerRegistry containerRegistry)
    {
        container = containerRegistry.GetContainer();

        RegisterRealServices()
    }

    private void RegisterRealServices()
    {
        container.Register<IBookingService, RealBookingService>(Reuse.Singleton);
    }

user presses a menu option to use fake services now.So Unregister the real ones and use the fake one.

However what I have done below does not seem to work because I keep getting redirected to the "RealBookingService" and not to the "FakeBookingService"

How can I do it?

    private void RegisterFakeServices()
    {
        container.Unregister<IBookingService>();

        container.Register<IBookingService,FakeBookingService>(
            Reuse.Singleton,
            ifAlreadyRegistered: IfAlreadyRegistered.Replace);
    }

Question: Is it possible to switch service implementation at runtime? How do you do it using DryIoc?

Answer 1

I am not an expert in Xamarin, but un(re)registering in DryIoc requires a special preparation (specifically for singleton). That's because service creation may be already cached.

Here is the wiki explaining this in detail: https://bitbucket.org/dadhi/dryioc/wiki/UnregisterAndResolutionCache