In my last article on IsBindableType, I have desribed, why AutoGenerateColumns does not work for Nullable types. Now I present a solution for this problem.

In order for your GridView, FormView, or DetailsView to autogenerate the field for your Nullable<T> property you have to subclass the control you are using: say GridView and override the IsBindableType method. In this overriden method, you have to add a check to see if a type is Nullable. This can be done in a following way according to Yitzhak Gootvilig's post:

public static bool IsNullableType(Type type)
{
    return type.IsGenericType && 
      type.GetGenericTypeDefinition() == typeof(Nullable<>);
}

Just put this code in some kind of reusable library since I have a feeling that ASP.NET controls will not be the last place you will need it

A full implementation of IsBindableType after the additional check will then look more or less like this:

public override bool IsBindableType(Type type)
{            
    return NullableHelper.IsNullableType(type) 
      || base.IsBindableType(type);
}

This simple hack has to be repeated for each of the *View controls. Fortunately it is not a common scenario where you have the AutoGenerateColumns property set to true .

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