should we set ItemsSource again or update view model

Question

I have a view model (an ObservableCollection list) set as ItemsSource for a ListBox. When I refresh this view model (get new data from network), should I set ItemsSource again, or just let it notify the ListBox ?

Which solution gains the most performance ?

P/S: Answer targeting Windows Phone 7 is prefered.

Answer 1

If you have your ListBox`s ItemSource set to an ObservableCollection there is nothing you need to do. Just add/remove items to/from the ObservableCollection.