Register a single View as the View for Multiple ViewModels - MVVMCross

Question

• MMVMCross
• Android
• Windows 8

We had a View, call it FruitView displaying a ViewModel called FruitViewModel. The FruitViewModel can display lists of a particular type of fruit.

This all worked fine.

For a couple of reasons we created AppleViewModel and PearViewModel that inherit from FruitViewModel. They do not do anything, all calls are made to the base viewmodel.

I want to register the FruitView as the View for AppleViewModel and PearViewModel when I try and navigate to them using MvxNavigatingObject.ShowViewModel.

I cannot see how to override the default linking of Views to ViewModels. I read one post that suggested overriding GetViewModelViewLookup in the Setup class but that does not seem to exist. I also looked at CustomPresenters but that did not look like the right approach.

Anyone else done this?

Thanks

Pat

Answer 1

After spotting this question How to navigate to a ViewModel that extends an abstract class? (not one of the suggesting when i was posting) I found InitializeViewLookup that can be overridden in each platform's Setup.cs. I am augmenting the current mappings rather than replacing so have called base.InitializeViewLookup first.

protected override void InitializeViewLookup()
{
    base.InitializeViewLookup();

    var viewModelViewLookup = new Dictionary<Type, Type>()
    {
        { typeof(AppleViewModel), typeof(FruitView) },
        { typeof(PearViewModel), typeof(FruitView) }
       };

    var container = Mvx.Resolve<IMvxViewsContainer>();
    container.AddAll(viewModelViewLookup);
}

Thanks

Pat