title: How to get the changed item in the NotifyCollectionChangedEventArgs?
body: <p>I have made an ObservableCollection&lt;T> that fires a CollectionChangedEvent every time a Property of the objects in the collection (T: INPC) is changed. I want to know which property of T has fired the CollectionChangedEvent, so I tried the following:</p>
  
  <pre><code>    void item_PropertyChanged(object sender, PropertyChangedEventArgs e)
      {
          OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset, e));
      }
  </code></pre>
  
  <p>I pass the PropertyChangedEventArgs e to the constructor of the NotifyCollectionChangedEventArgs.</p>
  
  <p>As per Intellisense, the 2nd constructor takes two parameters: a NotifyCollectionChangedAction, and an object called "changedObject", which is described as "the item that has been affected by the change".</p>
  
  <p>So I thought that I could grab that object in the CollectionChangedEventHandler and check for the PropertyName, but oh! surprise! the NotifyCollectionChangedEventArgs does not expose a "ChangedObject" property (I can see Action, NewItems, OldItems, NewStartingIndex, OldStartingIndex).</p>
  
  <p>Any ideas on how to achieve this? And by the way, what use does it have to construct the NotifyCollectionChangedEventArgs with an object which you cannot access later?</p>