Question

1. What do you people think about this solution to encapsulate a collection and be able to know when an iten is added/removed.

2. How can I add a clicable link to the xml description?

   // Why does DoNotExposeGenericLists recommend that I expose Collection instead of List? by David Kean"
   // http://blogs.msdn.com/b/codeanalysis/archive/2006/04/27/585476.aspx
   public class CollectionEx<T> : Collection<T>
   {
   public event EventHandler ItemAdded;
   public event EventHandler ItemRemoved;
   
   public CollectionEx()//:base()
   {
   }
   
   protected override void InsertItem(int index, T item)
   {
       base.InsertItem(index, item);
       OnSectionAdded(EventArgs.Empty);
   }
   
   protected override void RemoveItem(int index)
   {
       base.RemoveItem(index);
       OnSectionRemoved(EventArgs.Empty);
   }
   
   public new void Add(T item)
   {
       base.Add(item);
       OnSectionAdded(EventArgs.Empty);
   }
   public new bool Remove(T item)
   {
       bool ok = base.Remove(item);
       OnSectionRemoved(EventArgs.Empty);
       return ok;
   }
   
   protected override void ClearItems()
   {
       base.ClearItems();
   }
   
   protected virtual void OnSectionRemoved(EventArgs e)
   {
       EventHandler handler = this.ItemRemoved;
       if (handler != null)
       {
           handler(this, e);
       }
   }
   
   protected virtual void OnSectionAdded(EventArgs e)
   {
       EventHandler handler = this.ItemAdded;
       if (handler != null)
       {
           handler(this, e);
       }
   }
   

   }

Answer 1

You can use ObservableCollection<T> for this purpose. No need to write it yourself.

Besides: When subclassing Collection<T> it’s enough to override the protected virtual methods. All other public methods will invoke them.
If you additionally hide the non-virtual ones the way you did, events might be triggered multiple times (and in your case, when clearing the collection, no event will be triggered).