```
public ObservableCollection<Activity> activities = 
    new ObservableCollection<Activity> { };

public class Activity{
    public ObservableCollection<Event> Events { get; set; }
}

public class Event : INotifyPropertyChanged
{
    private int _Status;
    public int Status
    {
        get { return _Status; }
        set 
        {
            _Status = value;
            OnPropertyChanged("Status");
        } 
    }
}

```

Supposing that `Status` property of an `Event` was changed. `OnPropertyChanged("Status")` will be called, right?

But i want that collection `activities` be notified too about this `Event` change.

Any way to do it??

**Trying to resume:** 
This scenario is described above. 
Imagine some change in some Event.
I need that the collection activities, that has inside of it the parent activity of this event, be notified about this change... so i can call a method to update the event showed in some place of my interface. And in this interface is just visible the activities collection.

*It is because of this that the collection must also be notified.*