I have a LocalDataSourceProvider bound to a DataTable. Some of the columns allow nulls and some of the values in them are DBNull. I would like to be able to display a count of the values that aren't null. I've created my own aggregate function and I can add that to some of my AggregatePropertyDescriptions programmatically. I do have an example, but apparently I'm only allowed to upload images.
The questions I've got are:
Is there any easier way to do this?
Can I make this aggregate function appear in the UI in the Field List, so users can select it?
I only appear to be able to apply this to my nullable int property, and not my string property. Is that something I should be expecting?