I would like to create model binding functionality so a user can enter ',' '.' etc for currency values which bind to a double value of my ViewModel.

I was able to do this in MVC 1.0 by creating a custom model binder, however since upgrading to MVC 2.0 this functionality no longer works.

Does anyone have any ideas or better solutions for performing this functionality? A better solution would be to use some data annotation or custom attribute.

public class MyViewModel
{
    public double MyCurrencyValue { get; set; }
}

A preferred solution would be something like this...

public class MyViewModel
{
    [CurrencyAttribute]
    public double MyCurrencyValue { get; set; }
}

Below is my solution for model binding in MVC 1.0.

public class MyCustomModelBinder : DefaultModelBinder
{
    public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        object result = null;

        ValueProviderResult valueResult;
        bindingContext.ValueProvider.TryGetValue(bindingContext.ModelName, out valueResult);
        bindingContext.ModelState.SetModelValue(bindingContext.ModelName, valueResult);

        if (bindingContext.ModelType == typeof(double))
        {
            string modelName = bindingContext.ModelName;
            string attemptedValue = bindingContext.ValueProvider[modelName].AttemptedValue;

            string wantedSeperator = NumberFormatInfo.CurrentInfo.NumberDecimalSeparator;
            string alternateSeperator = (wantedSeperator == "," ? "." : ",");

            try
            {
                result = double.Parse(attemptedValue, NumberStyles.Any);
            }
            catch (FormatException e)
            {
                bindingContext.ModelState.AddModelError(modelName, e);
            }
        }
        else
        {
            result = base.BindModel(controllerContext, bindingContext);
        }

        return result;
    }
}