INotifyCollectionChangedExample.cs

public TestView : View
{
    private static void OnItemSourceChanged(BindableObject bindable, object oldvalue, object newvalue)
    {
        var self = (TestView) bindable;
        var oldCollection = oldvalue as INotifyCollectionChanged;
        var newCollection = newvalue as INotifyCollectionChanged;

        if (oldCollection != null)
            oldCollection.CollectionChanged -= self.OnItemSourceCollectionChanged;

        if (newCollection != null)
            newCollection.CollectionChanged += self.OnItemSourceCollectionChanged;

        self.UpdateItems(); // your custom method
    }
}