Why is ReadOnlyObservableCollection.CollectionChanged not public?

Question

Why is ReadOnlyObservableCollection.CollectionChanged protected and not public (as the corresponding ObservableCollection.CollectionChanged is)?

What is the use of a col

Answer 1

You might vote for the bug entry on Microsoft Connect that describes this issue: https://connect.microsoft.com/VisualStudio/feedback/details/641395/readonlyobservablecollection-t-collectionchanged-event-should-be-public

Update:

The Connect portal has been shutdown by Microsoft. So the link above does not work anymore.

My Win Application Framework (WAF) library provides a solution: ReadOnlyObservableList class:

public class ReadOnlyObservableList<T> 
        : ReadOnlyObservableCollection<T>, IReadOnlyObservableList<T>
{
    public ReadOnlyObservableList(ObservableCollection<T> list)
        : base(list)
    {
    }

    public new event NotifyCollectionChangedEventHandler CollectionChanged
    {
        add { base.CollectionChanged += value; }
        remove { base.CollectionChanged -= value; }
    }

    public new event PropertyChangedEventHandler PropertyChanged
    {
        add { base.PropertyChanged += value; }
        remove { base.PropertyChanged -= value; }
    }
}

Answer 2

Here's the solution: CollectionChanged events on ReadOnlyObservableCollection

You have to cast the collection to INotifyCollectionChanged.