Dynamic typed ViewPage

Question

Is this possible? Here\'s what I\'m trying:

    public ActionResult Index()
    {
        dynamic p = new { Name = \"Test\", Phone = \"111-2222\" };
                


        

Answer 1

What benefit were you hoping to get from using the dynamic type here?

Using the ViewData dictionary is a very easy way of adding arbitrary objects/items to your view output.

You don't need reflection to get the property names within your View. Just use ViewData.Keys to get the collection of names.

Edit: I've just learned a bit more about dynamics myself and I think maybe you need to create your own dynamic object class that inherits from DynamicObject. You'll want to have a private dictionary in that class and then override TrySetMember and TryGetMember.

Edit Aside: I think one advantage of a strongly typed ViewModel is that you can accept it as a parameter in your POST Action methods. The MVC framework will handle the model binding and in the action method you simply have an instance of your ViewModel class. I don't think you'll have that advantage with a dynamic even if they do work.

Edit Result: Well, I tried using a class derived from DynamicObject, but VS2010 crashes when it tries to render the view. I don't get any exception, just a hard crash and Visual Studio restarts. Here's the code I came up with that causes the crash.

The custom dynamic class:

public class DynViewModel : DynamicObject
{
    private Dictionary ViewDataBag;
    public DynViewModel()
    {
        this.ViewDataBag = new Dictionary();
    }
    public override bool TrySetMember(SetMemberBinder binder, object value)
    {
        this.ViewDataBag[binder.Name] = value;
        return true;
    }
    public override bool TryGetMember(GetMemberBinder binder, out object result)
    {
        result = this.ViewDataBag[binder.Name];
        return true;
    }
}

In the controller:

public ActionResult DynamicView()
{
    dynamic p = new DynamicViewModel.Models.DynViewModel();
    p.Name = "Test";
    p.Phone = "111-2222";

    return View(p);
}

My view is basically the same as what is listed in the question:

Name: <%=Model.Name %>
Phone: <%=Model.Phone %>

My Conclusion: This might work, but in the Beta 1 of VS2010 I can't figure out why my code causes Visual Studio to crash. I'll try it again in VS2010 Beta 2 when it is released because it is an interesting exercise in learning about dynamics. However, even if this were to work, I still don't see any advantage over using the ViewData dictionary.

Phil Haack to the rescue! Here's a blog post by Phil Haack that might help you out. It looks like it is what you were looking for. Fun With Method Missing and C# 4