title: ComboBox items.count doesn't match DataSource
body: <p>I have a ComboBox that is bound to a DataSource. I want to dynamically add items to the ComboBox based on certain conditions. So what I've done is add the options to a new list, and then change the DataSource of the ComboBox like so:</p>
  
  <pre><code>cbo.DataSource = null;
  cbo.DataSource = cbos;
  cbo.DisplayMember = "Title";
  cbo.ValueMember = "Value";
  </code></pre>
  
  <p>Then, I check <code>cbo.Items.Count</code>, and it has not incremented - it does not equal the count of the DataSource. Any ideas what I can do here?  </p>
  
  <p>Note this is WinForms and not ASP.NET.</p>