Hi,

You lost me a little there when you mentioned UltraDataSource. If you are binding to a List, where does UltraDataSource come into it?

Anyway, the grid will display the properties that the DotNet BindingManager tells it to. There's really very little control over this in the grid itself.

I think if you bind the grid to BindingList<x>, then this list implements ITypedList and returns only the properties of x. 

There are several ways you can get what you want here, though.

1. Use a BindingList<y>, instead of BindingList<x>. This is pretty obvious and I assume since you are posting here, it's probably not an option for you.
2. Use unbound columns. You could add an unbound column to the grid for each property of y. You would do this in the InitializeLayout event. You would then use InitializeRow to populate the grid cells from the underlying ListObject of the row after casting it into type y. For any editable fields, you would have to update the ListObject of the row, probably in the BeforeCellUpdate event of the grid.
   
3. You could derive from BindingList<x> and re-implement ITypedList to include the properties of type y. This would mean creating derived property descriptors. It's a bit tricky if you haven't done it before and has essentially the same problem as option 1.
   

I went with option 3, and it was terribly easy.  I grabbed an example from http://msdn.microsoft.com/en-us/library/system.componentmodel.itypedlist.aspx and extended binding list.

 I changed the constructor from this link to accept a list of interface names and reworked the guts to combine all applicable properties.

// Get the 'shape' of the list.

// Only get the public properties marked with Browsable = true.

var propertyList = new List<PropertyDescriptor>(objectProperties.Count);

if (interfaceType != null){