用于获取Collection的添加/删除事件的泛型类

Question

1. 你怎么看待这个封装集合的解决方案,并且能够知道何时添加/删除它.

2. 如何在xml描述中添加clicable链接？

   // 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

你可以用它ObservableCollection<T>来达到这个目的.不需要自己写.

此外:当子类化Collection<T>它足以覆盖受保护的虚拟方法.所有其他公共方法都将调用它们.
如果您按照自己的方式另外隐藏非虚拟事件,则可能会多次触发事件(在您的情况下,清除集合时,不会触发任何事件).