I have a requirement to filter the RadGridView on null values (“Is null” and “Is not null”). Unfortunately we can’t just use the distinct filtering as this only gives the options based on data already loaded in the grid. We have to be able to filter the data on “is null” or “is not null” before the data may be loaded.
Ideally we would like to add some extra options in the dropdown in the screenshot. Is this possible?
I have found this blog post http://blogs.telerik.com/blogs/posts/09-11-20/custom_filtering_with_radgridview_for_silverlight.aspx detailing the creation of a custom FilterControl, but that would mean re-implementing the entire control, when we would like to just extend the existing control somehow.
Is that possible or must we create our own FilterControl for the column?
Thanks,
Pete