The parameter conversion from type 'System.String' to type ''X' failed because no type converter can convert between these types

Question

I\'m stumped with this one and your help would be most appreicated.

I get the error:

The parameter conversion from type \'System.String\' to t

Answer 1

I had the same error but the cause was different from the accepted answer. Adding a custom ModelBinder fixed it for me.

I created a CData class as described here

How do you serialize a string as CDATA using XmlSerializer? (it's the last answer unless it got voted up because it's a great solution)

I serialize my ViewModel to XML. When I set a type in a property in my ViewModel to CData, it will automatically be serialized to a CData section and deserialized to a CData field. (which is great!)

When I do a post action in my view I want to keep some fields in my ViewModel so they are added as Html.HiddenFor in the form.

When a submit is done, an error occurs (the one in the title). The model binder tries to bind a string field to a CData field which fails.

A custom model binder for the CData type fixes this

public class CDataModelBinder : IModelBinder
{
    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        var result = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
        return new CData(result.AttemptedValue);
    }
}

Global.asax

 ModelBinders.Binders.Add(typeof(CData), new CDataModelBinder());