ASP.NET MVC 3 DataBinder.Eval on Viewmodel object throws “does not contain property”

Question

I have a view that was using a standard Model but now I need to add information from two different models on the page. I created a ViewModel after doing some research to handle this. Now I am getting an error when tring to show my view saying:

DataBinding: 'VirtualAuthtech.ViewModels.CMSCalculatorViewModel' does not contain a property with the name 'WORKCY'.

Here's my viewmodel

namespace VirtualAuthtech.ViewModels
{
    public class CMSCalculatorViewModel
    {
        public CPT CPT { get; set; }
        public GPCI GPCI { get; set; }
    }
}

CPT is the first model I was originally using and then I need to add GPCI

Here is the ActionResult for my view

public ActionResult _CMSCalculator()
        {
            string CPTCode = string.Empty;
            string MOD = string.Empty;
            string GPCIPayID = "31146";
            string GPCIYear = "2011";
            if (Request.Params["CPT1"] != null)
            {
                CPTCode = Request.Params["CPT1"];
                MOD = Request.Params["MOD"];
            }
            return PartialView("_CMSCalculatorPanel", (string.IsNullOrEmpty(CPTCode) ? null as CMSCalculatorViewModel : CPTDataHelper.GetCPTGPCI(CPTCode, MOD, GPCIPayID, GPCIYear)));
        }

Here is the method to get the data from my models

    public static CMSCalculatorViewModel GetCPTGPCI(string CPTCode, string MOD, string GPCIPayID, string GPCIYear)
    {
        using (var DB = new VADataContext())
        {
            var view = new CMSCalculatorViewModel();
            if (String.IsNullOrWhiteSpace(MOD))
            {
                view.CPT = (from cpt in DB.CPTs
                            where cpt.CPT1 == CPTCode
                            select cpt).FirstOrDefault<CPT>();
                view.GPCI = (from gpci in DB.GPCIs
                             where gpci.PAYID == GPCIPayID && gpci.YEAR == GPCIYear
                             select gpci).FirstOrDefault<GPCI>();
            }
            else
            {
                view.CPT = (from cpt in DB.CPTs
                            where cpt.CPT1 == CPTCode && cpt.MOD == MOD
                            select cpt).FirstOrDefault<CPT>();
                view.GPCI = (from gpci in DB.GPCIs
                             where gpci.PAYID == GPCIPayID && gpci.YEAR == GPCIYear
                             select gpci).FirstOrDefault<GPCI>();
            }
            return view;
        }
    }

Now my view is using the new ViewModel and I'm trying to display a field:

<div style='float:left; width: 35px; margin: 0; padding: 0; text-align: center; color: #094ab2'>@VirtualAuthtech.CallbackPanelHelper.GetFieldNumber(Model, "WORKCY")</div>

And I'm getting an error in this piece of code:

public static double GetFieldNumber(object data, string fieldName)
        {
            object text = DataBinder.Eval(data, fieldName);
            if (text == null || text.ToString() == string.Empty)
                return 0;
            double number = Convert.ToDouble(text);
            return number;
        }

It's saying my model does not contain the property of the field I'm looking for. Do I need to tell it to look in the CPT part of my view model?

This is the first ViewModel I've ever created so I might be going about this all wrong. Any help to send me in the right direction would be greatly appreciated!

Answer 1

Why the call to GetFieldNumber? What would be wrong with the following line:

<div style='float:left; width: 35px; margin: 0; padding: 0; text-align: center; color: #094ab2'>@Model.CPT.WORKCY</div>

But if you have to use run-time binding, then maybe the line in your function should be:

object text = DataBinder.Eval((CMSCalculatorViewModel)data.CPT, fieldName);

Answer 2

I was able to get it working using this code.

<div style='float:left; width: 35px; margin: 0; padding: 0; text-align: center; color: #094ab2'>@if(Model == null) { <text>0</text> } else { @VirtualAuthtech.CallbackPanelHelper.GetFieldNumber(Model.CPT, "WORKCY") }</div>

However, I have a lot of other fields in this view. I would rather not have to check if the model is null on every one of them. If you have another solution please share.