Csharp/CSharp Tutorial/Data Structure/Collection Event

User defined collection with events

using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Text;
public class NotificationList<T> : Collection<T>{
    public event EventHandler<ItemInsertedArgs<T>> ItemAdded;
    protected override void InsertItem(int index, T item){
        EventHandler<ItemInsertedArgs<T>> handler = ItemAdded;
        if (handler != null){
            handler(this, new ItemInsertedArgs<T>(index, item));
        }
        base.InsertItem(index, item);
    }
}
public class ItemInsertedArgs<T> : EventArgs{
    public int Index;
    public T Item;
    public ItemInsertedArgs(int index, T item)
    {
        this.Index = index;
        this.Item = item;
    }
}
public class MainClass
{
    public static void Main()
    {
        NotificationList<int> list = new NotificationList<int>();
        list.ItemAdded += delegate(object o, ItemInsertedArgs<int> args) {
            Console.WriteLine("A new item was added to the list: {0} at index {1}",args.Item, args.Index);
        };
        for (int i = 0; i < 10; i++)
        {
            list.Add(i);
        }
    }
}

A new item was added to the list: 0 at index 0
A new item was added to the list: 1 at index 1
A new item was added to the list: 2 at index 2
A new item was added to the list: 3 at index 3
A new item was added to the list: 4 at index 4
A new item was added to the list: 5 at index 5
A new item was added to the list: 6 at index 6
A new item was added to the list: 7 at index 7
A new item was added to the list: 8 at index 8
A new item was added to the list: 9 at index 9