Oct 29, 2014 12:46 AM|Fei Han - MSFT|LINK
Thanks for your post.
As for your problem, you could refer to the following sample to populate dropdownlist.
XDocument doc = XDocument.Load(Server.MapPath("Data/XMLFile1.xml"));
if (doc != null)
var items = from i in doc.Descendants("ITM")
DropDownList1.DataSource = items.ToList();
Besides, here is about XDocument.Descendants Method, you could check the below link to get more information about it.
Hope it will be helpful to you.