Linq To XML:获得该结点的所有祖先结点，也可以说父结点吧

XElement firstParticipant; 
 
//  A full document with all the bells and whistles. 
XDocument xDocument = new XDocument( 
  new XDeclaration("1.0", "UTF-8", "yes"), 
  new XDocumentType("BookParticipants", null, "BookParticipants.dtd", null), 
  new XProcessingInstruction("BookCataloger", "out-of-print"), 
  //  Notice on the next line that we are saving off a reference to the first 
  //  BookParticipant element. 
  new XElement("BookParticipants", firstParticipant = 
    new XElement("BookParticipant", 
      new XComment("This is a new author."), 
      new XProcessingInstruction("AuthorHandler", "new"), 
      new XAttribute("type", "Author"), 
      new XElement("FirstName", 
        new XText("Joe"), 
        new XElement("NickName", "Joey")), 
      new XElement("LastName", "Rattz")), 
    new XElement("BookParticipant", 
      new XAttribute("type", "Editor"), 
      new XElement("FirstName", "Ewan"), 
      new XElement("LastName", "Buckingham")))); 
 
foreach (XElement element in firstParticipant. 
  Element("FirstName").Element("NickName").Ancestors()) 
{ 
  Console.WriteLine(element.Name); 
} 

输出

FirstName 
BookParticipant 
BookParticipants 

注意这个方法

foreach (XElement element in firstParticipant.

Element("FirstName").Element("NickName").Ancestors())

打印出的顺序是由里层父结点向外层父结点

如果打印结果要包含自身结点那么就这么写

foreach (XElement element in firstParticipant.

Element("FirstName").Element("NickName").AncestorsAndSelf())

{

Console.WriteLine(element.Name);

}

打印结果是这样

NickName

FirstName

BookParticipant

BookParticipants

那么以上递归父结点的方法都是由里层向外层显示，还有个方法是把递归顺序倒过来

把上面那个循环的代码改成这样

foreach (XElement element in firstParticipant.Descendants())

那么打印结果就是从外层到里层显示

FirstName

NickName

LastName

相应的，它也有打印息自身的方法，命名差不多，也是XXXXSelf

foreach (XElement element in firstParticipant.DescendantsAndSelf())

打印结果

BookParticipant

FirstName

NickName

LastName