title: Implementing (not handling) CollectionChanged event
body: <p>I have created a class that extends the base class <code>ListView.ColumnHeaderCollection</code> (found in <code>System.Windows.Forms</code>) and I want to be able to receive a notification of when the collection is changed via INotifyCollectionChanged.</p>
  
  <p>So far, I have:</p>
  
  <pre><code>public class MyCollection : ListView.ColumnHeaderCollection, INotifyCollectionChanged { ... }
  </code></pre>
  
  <p>In my initialization method, I am assigning the delegate my own method <code>OnCollectionChanged()</code>.</p>
  
  <pre><code>UserSettings.Instance.Columns.CollectionChanged += new System.Collections.Specialized.NotifyCollectionChangedEventHandler(OnCollectionChanged);
  </code></pre>
  
  <p>For those who are curious, my delegate looks like:</p>
  
  <pre><code>public void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
  {
      Settings_Save();
  }
  </code></pre>
  
  <p>And so we arrive at my problem. I don't know how to implement the interface member required by <code>INotifyCollectionChanged</code>.</p>
  
  <pre><code>'_Namespace_.MyCollection' does not implement interface member 'System.Collections.Specialized.INotifyCollectionChanged.CollectionChanged'
  </code></pre>
  
  <p>Many thanks from this C# newbie!</p>