Q:

Why ObservableCollection is not updated on items change?

I noticed that ObservableCollection in WPF reflects changes in GUI only by adding or removing an item in the list, but not by editing it. 
That means that I have to write my custom class MyObservableCollection instead.
What is the reason for this behaviour?
Thanks

A:

The ObservableCollection has no way of knowing if you make changes to the objects it contains - if you want to be notified when those objects change then you have to make those objects observable as well (for example by having those objects implement INotifyPropertyChanged)

