LINQ To XML:修改element, a comment, text node

//  we will use this to reference to one of the elements in the XML tree. 
XElement firstParticipant; 
 
XDocument xDocument = new XDocument( 
  new XElement("BookParticipants", firstParticipant = 
    new XElement("BookParticipant",  
      new XComment("This is a new author."), 
      new XAttribute("type", "Author"), 
      new XElement("FirstName", "Joe"), 
      new XElement("LastName", "Rattz")))); 
 
Console.WriteLine("Before updating nodes:"); 
Console.WriteLine(xDocument); 
 
//  Now, lets update an element, a comment, and a text node. 
firstParticipant.Element("FirstName").Value = "Joey"; 
firstParticipant.Nodes().OfType<XComment>().Single().Value =  
  "Author of Pro LINQ: Language Integrated Query in C# 2008."; 
((XElement)firstParticipant.Element("FirstName").NextNode) 
  .Nodes().OfType<XText>().Single().Value = "Rattz, Jr."; 
 
Console.WriteLine("After updating nodes:"); 
Console.WriteLine(xDocument); 

输出

Before updating nodes: 
<BookParticipants> 
  <BookParticipant type="Author"> 
    <!--This is a new author.--> 
    <FirstName>Joe</FirstName> 
    <LastName>Rattz</LastName> 
  </BookParticipant> 
</BookParticipants> 
After updating nodes: 
<BookParticipants> 
  <BookParticipant type="Author"> 
    <!--Author of Pro LINQ: Language Integrated Query in C# 2008.--> 
    <FirstName>Joey</FirstName> 
    <LastName>Rattz, Jr.</LastName> 
  </BookParticipant> 
</BookParticipants>