title: C# Class Changed Event causing Object reference not set to an instance of an object
body: <p>I need an event to fire when I change a property.  When I run this code I get a Object reference not set to an instance of an object.  What am I doing wrong?  What is the correct way to instantiate an event, and fire it when a property is set?</p>
  
  <p>public member:</p>
  
  <pre><code>public event System.EventHandler ClassChanged;
  </code></pre>
  
  <p>property set:</p>
  
  <pre><code>ClassChanged(this, EventArgs.Empty);
  </code></pre>