Linq 2 Xml 这个该怎么取？
XML:

            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.LoadXml(context.Server.MapPath("config.xml"));

            xmlDoc.SelectSingleNode("");

            //var ss in xmlDoc



                                                                            
[解决办法]
mlDoc.SelectSingleNode("/Ips/ip[text()='221.7.213.111']");

linq版
            XDocument xdoc = null;
            using (var sr = System.IO.File.OpenText("config.xml"))
            {
                xdoc = XDocument.Load(sr);
            }
            var result = xdoc.Descendants("ip").FirstOrDefault(ip => ip.Value == "221.7.213.111");


[解决办法]
 XDocument root = XDocument.Load("test.xml");
            IEnumerable address = from el in root.Elements("Ips").Elements("ip")
                                  select el; 
 

            foreach (XElement el in address)
            {
                Console.WriteLine(el.Value);
            }