使用Linq使用C＃更新XML

//MY XML FILE STRUCTURE 
    <items>
       <item>
        <itemID>1</itemID>
        <isGadget>True</isGadget>
        <name>Star Wars Figures</name>
        <text1>LukeSkywalker</text1>
       </item>
    </items>
//TO READ DATA FROM XML BY ITEMID
XDocument xmlDoc = XDocument.Load(HttpContext.Current.Server.MapPath("data.xml"));
var items = from item in xmlDoc.Descendants("item")
            where item.Element("itemID").Value == itemID
            select new
            {
                itemID = item.Element("itemID").Value,
                isGadget = bool.Parse(item.Element("isGadget").Value),
                name = item.Element("name").Value,
                text1 = item.Element("text1").Value,
             }
         foreach (var item in items)
         {
            ....
         }
//MY XML FILE STRUCTURE 
    <items>
       <it