title: How to get the number of open MDI children
body: <p>In C#, how do you obtain the number of open MDI children windows? I could make my own counter, but I'm not sure if there's already some in-built functionality for this.</p>
  
  <p>I tried using <code>MdiChildren.Length</code> but this consistently returned <code>0</code> even though there were multiple MDI children open already.</p>
  
  <p>Thanks.</p>