title: WPF Extended Toolkit - CheckComboBox SelectedValue Ordering
body: <p>I'm having the situation where when I check items in the combo box it orders the comma delimited selectedvalue according to the order of the items in the drop down. So for example.</p>
  
  <p>If I have the following dropdown:</p>
  
  <pre><code>[] A
  [] B 
  [] C
  </code></pre>
  
  <p>And I then go ahead and first tick B then C and then A. The selectedvalue then shows A,B,C and not B,C,A. Which means that for some reason the values are being sorted after selection.  From tests it seems to sort the comma delimited selectedvalue to be in the same order as the order they appear in the dropdown. How can I disable this so that it doesn't sort the selectedvalue? I want to have the selected value read B,C,A in the order I selected them.</p>