Xamarin Forms VM First Nav - Passing Parameters

NavigationService.cs

public async Task PushAsync<T>(Action<T> initialize = null) where T : BaseViewModel 
{
	T viewModel;

	// First instantiate the view model
	// "IoC" is a static AutoFac IContainer property in the main Xam Forms Application class
	using (var scope = App.IoC.BeginLifetimeScope ()) {
		viewModel = App.IoC.Resolve<T> ();

	        if (initialize != null)
	        {
	            initialize.Invoke(viewModel);
	        }				
	}

	var view = InstantiateView (viewModel);

	await FormsNavigation.PushAsync ((Page)view);
}

ViewModel.cs

// Invoke the service like this
await _navService.PushAsync<DetailViewModel>(vm => 
    vm.InitializeDisplay("Interesting Stuff", anotherVariable, "more stuff")
);