Update an ObservableCollection with a background worker in MVVM

Question

Ok, I recently implemented a background worker to perform saving and loading of data.

However, getting this to work on a save command has proved difficult.

B

Answer 1

Where you've got code which adds the item to the observable collection (presumably in the view model), wrap that Add call in a Dispatcher.BeginInvoke call.

Admittedly that means the view model needs to know about the dispatcher, which then becomes awkward to test... fortunately it's not too hard to introduce your own IDispatcher interface and use dependency injection in the normal way.