using System;

using System.Collections.ObjectModel;

using System.Collections.Specialized;

using static System.Console;

​

public class Program

{

    public static void Main()

    {

        var obsColl = new ObservableCollection<string>

        {

            "Nome1",

            "Nome2",

            "Nome3",

            "Nome4"

        };

        obsColl.CollectionChanged += HandleChange;

        obsColl.Add("NovoNome");

    }

    private static void HandleChange(object sender, NotifyCollectionChangedEventArgs e)

    {

        foreach (var novoItem in e.NewItems)

        {

            WriteLine($"O item {novoItem} foi adicionado");

        }

    }

}