MVC 2 Conversion Disrupts the parameters passed to my Stored Procedure

I have a few textboxes that are not required. If the user enters nothing it is passed as 'null' in MVC 2. It was passed as '""' in MVC 1. What changes can I make to accomodate for this?

    public string Name { get; set; }
    public string Offer{ get; set; }
    public string AutoID { get; set; }


        using (SqlConnection connect = new SqlConnection(connections))
        {
            SqlCommand command = new SqlCommand("Info_Add", connect);
            command.Parameters.Add("autoID", SqlDbType.BigInt).Direction = ParameterDirection.Output;                
            command.Parameters.Add(new SqlParameter("name", Name));

            //Offer now returns a null value, which cannot be passed
            command.Parameters.Add(new SqlParameter("offer", Offer));
            command.CommandType = CommandType.StoredProcedure;

            connect.Open();
            command.ExecuteNonQuery();
            AutoID = command.Parameters["autoID"].Value.ToString开发者_StackOverflow();
        }

Change your model binder:

public class EmptyStringModelBinder : DefaultModelBinder
{
    public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        bindingContext.ModelMetadata.ConvertEmptyStringToNull = false;
        return base.BindModel(controllerContext, bindingContext);
    }
}

and then in global.asax:

ModelBinders.Binders.DefaultBinder = new EmptyStringModelBaseBinder();

This will revert to default settings from MVC 1. bindingContext.ModelMetadata.ConvertEmptyStringToNull property is responsible for conversion to null.

Check the properties with string.IsNullOrEmpty() and if its true then set some default value to it.

This way it works both for ASP.NET MVC 1 and ASP.NET MVC 2

Another way to override the ModelBinder behaviour is to override the GetPropertyValue, this is where the ConvertEmptyStringToNull magic happens:

namespace System.Web.Mvc
{
    class KeepEmptyStringsEmptyModelBinder : DefaultModelBinder
    {
        protected override object GetPropertyValue(ControllerContext controllerContext, ModelBindingContext bindingContext, ComponentModel.PropertyDescriptor propertyDescriptor, IModelBinder propertyBinder)
        {
            return propertyBinder.BindModel(controllerContext, bindingContext);
        }
    }
}

Brian