Caliburn.Micro WindowManager Cannot find view

Question

I have done some searching and I can't find anyone with my specific problem.

I have a Caliburn.Micro project and I successfully have a main view with sub-views inside it which is not a problem. My View Models are in a different assembly to my views.

This meant I had to override SelectAssemblies to include my view models project:

protected override IEnumerable<Assembly> SelectAssemblies()
    {
        var assemblies = base.SelectAssemblies().ToList();
        assemblies.Add(typeof(OrderViewModel).Assembly);

        return assemblies;
    }

Now, this is where my confusion starts. I successfully have a OrderView showing the OrderViewModel. Inside that there is a KeyboardViewModel with a KeyboardView. This all works fine so caliburn is finding the right assemblies etc.

However when I come to use the window manager to display a new view/viewmodel which is passed into the order view. I am getting a screen with the text "Cannot find view model for XX.ViewModels.Model."

This is my OrderViewModel

[Export(typeof(OrderViewModel))]
public class OrderViewModel : Screen
{
        private readonly IWindowManager windowManager;
        private ISession session;

        [ImportingConstructor]
        public OrderViewModel(IWindowManager windowManager, KeyboardViewModel keyboardViewModel)
        {
            TillDatabase.CreateInstance(ApplicationConfiguration.Instance.DatabaseConnectionString);
            this.windowManager = windowManager;
            this.Keyboard = keyboardViewModel;
            this.Keyboard.Order = this;
            this.Keyboard.Home();
        }


        public void ChangePriceBand()
        {
            windowManager.ShowWindow(new PriceBandSelectionViewModel(this));
        }

}

The thing is, I even tried this in ChangePriceBand

 windowManager.ShowWindow(new OrderViewModel(this.windowManager, new KeyboardViewModel()));

And this gets the same error. Even though a view has already been associated with the OrderViewModel previously!!

This is the PriceBandSelectionViewModel just in case.

[Export(typeof(PriceBandSelectionViewModel))]
public class PriceBandSelectionViewModel : Screen
{
    private OrderViewModel order;

    [ImportingConstructor]
    public PriceBandSelectionViewModel(OrderViewModel order)
    {
        this.order = order;
    }

    public ObservableCollection<PriceBandButtonViewModel> Buttons
    {
        get
        {
            var list = new ObservableCollection<PriceBandButtonViewModel>();
            var priceBands = this.order.Session.QueryOver<Application_Model_PriceBand>().List();
            foreach (var priceBand in priceBands)
            {
                PriceBandButtonViewModel button = new PriceBandButtonViewModel(priceBand, this);
                list.Add(button);
            }
            return list;
        }
    }


    public void ProcessButtonClick(Application_Model_PriceBand button)
    {
        this.order.ChangeCurrentPriceBand(button);
        base.TryClose();
    }

}

I'm just really confused to how Caliburn is setting up my main view, but the window manager isn't even though its the same ViewModel?

Answer 1

have you tried to remove OrderViewModel or put a breakpoint there, cant find view error might happen if it encountered error when initialising the exported class

public PriceBandSelectionViewModel()
{
    // this.order = order;
}

or add

assemblies.Add(typeof(PriceBandSelectionViewModel).Assembly);

Answer 2

This may be the same problem as I am experiencing as described here: Caliburn.Micro HelloWindowManager Sample - View location not working

To see if it is the same problem, try changing the call from

windowManager.ShowWindow(new PriceBandSelectionViewModel(this)); 

to

windowManager.ShowDialog(new PriceBandSelectionViewModel(this));.  

In my case, ShowDialog was able to locate the view no problem, but ShowWindow and ShowPopup were not.