Add / Remove Buttons disabled on a dataform

Question

Bear with me, this is possibly a very specific problem we've encountered here:

We have a silverlight application that gets its data from a WCF (not RIA) back end service. We are displaying a collection of addresses in a dataform for the program user to edit, add to, or remove addresses from the collection.

The Addresses are bound to the Dataform as an observable collection, and the AddressView class (partial class via WCF), has been extended to implement the IEditiableObject interface.

The problem we are having is that the add/remove buttons are disabled on the control. The kicker is that this was working previously, but seems to have stopped at some point while squashing bugs and refactoring, and we haven't been able locate any related code changes.

Looking into the actual code of the dataform, the add/remove buttons are always disabled because the control attempts to cast it's internal collection to an IEditiableCollectionView, which fails, and I'm not sure why.

Any leads or pointers to try is greatly appreciated.

Answer 1

Found the issue to the problem. The assembly version for System.Windows.Data was incorrectly pointing to the SL 3 version. When this was changed to the SL4 version, everything began to work properly again. There's a lesson in this: when in doubt, check your references!