LINQ to XML 进阶篇(三)

////检索属性type的值
            XElement val = new XElement("Value",
                new XAttribute("ID", "1243"),
                new XAttribute("Type", "int"),
                new XAttribute("ConvertableTo", "double"),
                "100");
            IEnumerable<XAttribute> xa =
                from att in val.Attributes()
                select att;
            foreach (XAttribute a in xa)
                if (a.Name.ToString()== "Type")
                    Console.WriteLine(a.Value);

    XElement cust = new XElement("PhoneNumbers",
                    new XElement("Phone",
                        new XAttribute("type", "home"),
                        "555-555-5555"),
                    new XElement("Phone",
                        new XAttribute("type", "work"),
                        "555-555-6666")
                );
            IEnumerable<XElement> elList =
                from el in cust.Descendants("Phone")
                select el;
            foreach (XElement el in elList)
                Console.WriteLine((string)el.Attribute("type"));

  ////查找具有特定属性的元素
            XElement root = XElement.Load("PurchaseOrder.xml");
            IEnumerable<XElement> address =
                from el in root.Elements("Address")
                where (string)el.Attribute("Type") == "Billing"
                select el;
            foreach (XElement el in address)
                Console.WriteLine(el);

  ////查找具有特定子元素的元素
            XElement root = XElement.Load("TestConfig.xml");
            IEnumerable<XElement> tests =
                from el in root.Elements("Test")
                where (string)el.Element("CommandLine") == "Examp2.EXE"
                select el;
            foreach (XElement el in tests)
                Console.WriteLine((string)el.Attribute("TestId"));