C# linq to xml 简单示例

data.xml

 <?xml version="1.0" encoding="utf-8" ?>
 <Data>
   <Products>
     <Product Name="West Side Story" Price="9.99" SupplierID="1" />
     <Product Name="Assassins" Price="14.99" SupplierID="2" />
     <Product Name="Frogs" Price="13.99" SupplierID="1" />
     <Product Name="Sweeney Todd" Price="10.99" SupplierID="3" />
   </Products>

   <Suppliers>
     <Supplier Name="Solely Sondheim" SupplierID="1" />
     <Supplier Name="CD-by-CD-by-Sondheim" SupplierID="2" />
     <Supplier Name="Barbershop CDs" SupplierID="3" />
   </Suppliers>
 </Data>

通过 linq to xml ，查找价格超过10的产品，并打印供应商名称与产品名称；

             XDocument doc = XDocument.Load("data.xml");
             var filtered = from p in doc.Descendants("Product")
                            join s in doc.Descendants("Supplier")
                            on (int)p.Attribute("SupplierID")
                            equals (int)s.Attribute("SupplierID")
                            where (decimal)p.Attribute("Price") >
                            select new
                            {
                                ProductName = (string)p.Attribute("Name"),
                                SupplierName = (string)s.Attribute("Name")
                            };

             foreach (var v in filtered)
             {
                 Console.WriteLine("SupplierName={0} , ProductName={1}", v.SupplierName, v.ProductName);
             }

输出

SupplierName=CD-by-CD-by-Sondheim , ProductName=Assassins
SupplierName=Solely Sondheim , ProductName=Frogs
SupplierName=Barbershop CDs , ProductName=Sweeney Todd

参考资料

1、深入理解C#(第2版)；