xml - Loading XDocument Descendants into a .NET MVC 3 Model -

i have repository attempts load xml document class. seems go alright until attempt access descendants elements in map config section.

this structure of xml file:

 <apps>   <item>     <id>1</id>     <engineversion>1.0</engineversion>     <mapconfig>       <minzoom>3</minzoom>       <maxzoom>18</maxzoom>       <startcenterlat>-28</startcenterlat>       <startcenterlng>135</startcenterlng>       <startzoom>3</startzoom>     </mapconfig>   </item> </apps> 

and repository method on controller:

public apprepository() {     allapps = new list<app>();      appdata = xdocument.load(httpcontext.current.server.mappath("~/app_data/apps.xml"));      var apps = app in appdata.descendants("item")                 select new app(                     (int)app.element("id"),                     (float)app.element("engineversion"),                     new mapconfig (                         (int)app.descendants("mapconfig").descendants("minzoom").firstordefault(),                         (int)app.descendants("mapconfig").descendants("maxzoom").firstordefault(),                         (float)app.descendants("mapconfig").descendants("startcenterlat").firstordefault(),                         (float)app.descendants("mapconfig").descendants("startcenterlng").firstordefault(),                         (int)app.descendants("mapconfig").descendants("startzoom").firstordefault()                     )                 );      allapps.addrange(apps.tolist<app>());  } 

this seems result in id , engine version values correctly being read app object mapconfig object seems have 0 set value of elements.

can see doing wrong?