title: Sort treelistex by displayname, both available and selected items per language
body: <p>I'm working with Sitecore 8 Update 2</p>
  
  <p>I'm looking for a way to sort all items ( mainly the available items ) from a treelistex by displayname per language.</p>
  
  <p>I've found some way to extend the list of selected items but not for the available items ( left column ).
  <a href="https://stackoverflow.com/questions/21462117/how-to-sort-the-selected-items-in-a-sitecore-treelist/21463608#21463608">How to sort the selected items in a Sitecore Treelist?</a></p>
  
  <p>I've also found this but i can't seem to get it to work ( SortBy )
  <a href="http://www.sitecore.net/learn/blogs/technical-blogs/john-west-sitecore-blog/posts/2012/10/more-enhancements-to-the-treelist-field-type-in-the-sitecore-aspnet-cms.aspx" rel="nofollow noreferrer">http://www.sitecore.net/learn/blogs/technical-blogs/john-west-sitecore-blog/posts/2012/10/more-enhancements-to-the-treelist-field-type-in-the-sitecore-aspnet-cms.aspx</a></p>
  
  <p>Can someone give me a clear explanation on how to achieve this ?</p>