title: How to know how many event handlers for an event?
body: <p>How to know how many event handlers for an event?</p>
  
  <p>I want a way to execute the following code:</p>
  
  <pre><code>// if (control.CheckedChanged.Handlers.Length == 0)
  {
      control.CheckedChanged += (s, e) =&gt;
      {
        // code;
      }
  }
  </code></pre>
  
  <p>Note: this code is out side the control class.</p>
  
  <p>Thanks in advance.</p>