List firing Event on Change

Question

I created a Class EventList inheriting List which fires an Event each time something is Added, Inserted or Removed:

public          


        

Answer 1

I have a Solution for when someone calls the Generic method from IList.add(object). So that you also get notified.

using System;
using System.Collections;
using System.Collections.Generic;

namespace YourNamespace
{
    public class ObjectDoesNotMatchTargetBaseTypeException : Exception
    {
        public ObjectDoesNotMatchTargetBaseTypeException(Type targetType, object actualObject)
            : base(string.Format("Expected base type ({0}) does not match actual objects type ({1}).",
                targetType, actualObject.GetType()))
        {
        }
    }

    /// 

    /// Allows you to react, when items were added or removed to a generic List.
    /// 
    public abstract class NoisyList : List, IList
    {
        #region Public Methods
        /******************************************/
        int IList.Add(object item)
        {
            CheckTargetType(item);
            Add((TItemType)item);
            return Count - 1;
        }

        void IList.Remove(object item)
        {
            CheckTargetType(item);
            Remove((TItemType)item);
        }

        public new void Add(TItemType item)
        {
            base.Add(item);
            OnItemAdded(item);
        }

        public new bool Remove(TItemType item)
        {
            var result = base.Remove(item);
            OnItemRemoved(item);
            return result;
        }
        #endregion

        # region Private Methods
        /******************************************/
        private static void CheckTargetType(object item)
        {
            var targetType = typeof(TItemType);
            if (item.GetType().IsSubclassOf(targetType))
                throw new ObjectDoesNotMatchTargetBaseTypeException(targetType, item);
        }
        #endregion

        #region Abstract Methods
        /******************************************/
        protected abstract void OnItemAdded(TItemType addedItem);

        protected abstract void OnItemRemoved(TItemType removedItem);
        #endregion
    }
}