EntityFramework EntityCollection Observing CollectionChanged

Question

I'm using EntityFramework database first in an application. I would like somehow to be notified of changes to an EntityCollection in my ViewModel. It doesn't directly support INotifyCollectionChanged (why?) and I haven't been successful in finding another solution.

Here's my latest attempt, which doesn't work because the ListChanged event doesn't appear to get raised:

public class EntityCollectionObserver<T> : ObservableCollection<T>, INotifyCollectionChanged where T : class
{
    public event NotifyCollectionChangedEventHandler CollectionChanged;

    public EntityCollectionObserver(EntityCollection<T> entityCollection)
        : base(entityCollection)
    {
        IBindingList l = ((IBindingList)((IListSource)entityCollection).GetList());
        l.ListChanged += new ListChangedEventHandler(OnInnerListChanged);
    }

    private void OnInnerListChanged(object sender, ListChangedEventArgs e)
    {
        if (CollectionChanged != null) 
            CollectionChanged(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
    }
}

Does anyone have any ideas how I might observe changes to an EntityCollection?

Dan

Answer 1

have you tried handling AssociationChanged Occurs when a change is made to a related end. (Inherited from RelatedEnd.)

It gives arguments showing whether an element was added or deleted and also exposes the element.