選擇元素LINQ到XML

Question

我有這個XML文件：

<?xml version="1.0" encoding="UTF-8" standalone="no"?> 
<games> 
    <game id="123456" name="501"> 
    <player id="1"> 
     <name>john</name> 
     <score>495</score> 
     <movesLeft>15</movesLeft> 
     <won>No</won> 
     <completed>uncompleted</completed> 
    </player> 
    <player id="2"> 
     <name> 
     konj 
     </name> 
     <score>501</score> 
     <movesLeft>15</movesLeft> 
     <won>No</won> 
     <completed>uncompleted</completed> 
    </player> 
    </game> 
</games> 

，我創建這個查詢，但它並不能編譯：

string path = @"D:\xml\dartDatabase.xml"; 
XElement file = XElement.Load(path); 

var query = from f in file.Element("games").Elements("game") 
      where (string)f.Attribute("id") == "123" 
      select (string)f.Element("name"); 

它強調的第一條線（約from部分），說錯誤是：

'Where'not found，你是否缺少對System.Core.dll的引用或使用System.Linq的指令

怎麼了？

Answer 1

添加using System.Linq;