C# linq to xml 簡單示例

data.xml

 1 <?xml version="1.0" encoding="utf-8" ?>
 2 <Data>
 3   <Products>
 4     <Product Name="West Side Story" Price="9.99" SupplierID="1" />
 5     <Product Name="Assassins" Price="14.99" SupplierID="2" />  
 6     <Product Name="Frogs" Price="13.99" SupplierID="1" />
 7     <Product Name="Sweeney Todd" Price="10.99" SupplierID="3" />
 8   </Products>
 9 
10   <Suppliers>
11     <Supplier Name="Solely Sondheim" SupplierID="1" />
12     <Supplier Name="CD-by-CD-by-Sondheim" SupplierID="2" />
13     <Supplier Name="Barbershop CDs" SupplierID="3" />
14   </Suppliers>
15 </Data>

通過 linq to xml ，查找價格超過10的產品，並列印供應商名稱與產品名稱；

 1             XDocument doc = XDocument.Load("data.xml");
 2             var filtered = from p in doc.Descendants("Product")
 3                            join s in doc.Descendants("Supplier")
 4                            on (int)p.Attribute("SupplierID")
 5                            equals (int)s.Attribute("SupplierID")
 6                            where (decimal)p.Attribute("Price") > 10
 7                            select new
 8                            {
 9                                ProductName = (string)p.Attribute("Name"),
10                                SupplierName = (string)s.Attribute("Name")
11                            };
12 
13             foreach (var v in filtered)
14             {
15                 Console.WriteLine("SupplierName={0} , ProductName={1}", v.SupplierName, v.ProductName);
16             }

輸出

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

參考資料

1、深入理解C#(第2版)；