Do I have to implement a ViewModel when using multiple Models in one View?

Question

I want the user to fill in 2 forms on the View. Each form should "represents" a Model. So the View should use 2 Models.

Do I need to implement a ViewModel or can I implement a View with 2 Models?

I already tried with Tuple<Item1, Item2> and failed

Answer 1

100% you should create a viewmodel that comprises of the two models you need.

public class MainViewModel
{
    public ModelA ModelA { get; set; }
    public ModelB ModelB { get; set; }
}

You should keep the association of one view -> one viewmodel class. I keep to this in my MVC apps, and it helps me keep the views simpler.

I would never try to mix two viewmodels in one view; that's making things tricker for yourself.