使用LINQ根据where子句读取CDATA部分

Question

I am trying to read CDATA section of an xml node based upon the where clause.

<Book>
  <BookItem ISBN="SKS84747"><![CDATA[20]]> </BookItem>
  <BookItem ISBN="LHKGOI84747"><![CDATA[50]]> </BookItem>
  <BookItem ISBN="PUOT84747"><![CDATA[20]]> </BookItem>
</Book>

This code gives me all the CDATA sections,

var value = from v in x.Descendants("BookItem").OfType<XCData>()
                                select (string)v.Value;

How to put where clause based on ISBN ? How can I read this CDATA using LINQ to XML.

Answer 1

var value = x.DescendantNodes().OfType<XCData>()
                .Where(m => m.Parent.Name == "BookItem" && m.Parent.Attribute("ISBN").Value == "PUOT84747")
                .ToList();

or

before ToList()

.Select(cdata => cdata.Value.ToString());

Answer 2

var xml = Resource1.String1;
var doc = XDocument.Parse(xml);
var isbn = "SKS84747";
var query = string.Format("BookItem[@ISBN='{0}']", isbn);
var book = doc.Root.XPathSelectElement(query);

if (book != null)
    Console.WriteLine(book.Value);

OR

var book =
    doc.Root.Descendants("BookItem").Where(
        x => x.Attribute("ISBN") != null && x.Attribute("ISBN").Value == isbn).Select(x => x.Value).
        FirstOrDefault();

OR

var book = (from item in doc.Root.Descendants("BookItem")
            where item.Attributes("ISBN").Any() && item.Attribute("ISBN").Value == isbn
            select item.Value).FirstOrDefault();