Question

I want to have Dictionary that would be ‘Observable’ in order to throw events when its item changing (Remove or Add).

In other class I created such dictionary and set Binding to ListBox.ItemsSourseProperty.
The Binding work well. I can see the items.

But something is wrong: the event PropertyChanged always null.

Can anyone help?

Thanks in advance!

class ObservableDictionary<TKey, TValue> : 
    Dictionary<TKey, TValue>, 
    INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    public new void Remove(TKey obj)
    {
        base.Remove(obj);

        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs("Remove"));
        }
    }
}

Answer 1

You should not call PropertyChanged for a collection change event. You need to implement INotifyCollectionChanged.