net处理有命名空间的xml文件的方法

xml文件

<?xml version="1.0" encoding="utf-8" ?>
<bk:bookstore xmlns:bk="http://www.contoso.com/books">
  <bk:book genre="autobiography" publicationdate="1981-03-22" ISBN="1-861003-11-0">
    <bk:title>The Autobiography of Benjamin Franklin</bk:title>
    <author>
      <first-name>Benjamin</first-name>
      <last-name>Franklin</last-name>
    </author>
    <price>8.99</price>
  </bk:book>
  <bk:book genre="autobiography" publicationdate="1981-03-22" ISBN="1-861003-11-0">
    <bk:title>2222</bk:title>
    <author>
      <first-name>Benjamin</first-name>
      <last-name>Franklin</last-name>
    </author>
    <price>8.99</price>
  </bk:book>
  <book genre="novel" publicationdate="1967-11-17" ISBN="0-201-63361-2">
    <title>The Confidence Man</title>
    <author>
      <first-name>Herman</first-name>
      <last-name>Melville</last-name>
    </author>
    <price>11.99</price>
  </book>
  <book genre="philosophy" publicationdate="1991-02-15" ISBN="1-861001-57-6">
    <title>The Gorgias</title>
    <author>
      <name>Plato</name>
    </author>
    <price>9.99</price>
  </book>
</bk:bookstore>

C#代码

        string path = MapPath("~/app_data/XMLFile.xml");
        XPathDocument document = new XPathDocument(path);
        XPathNavigator navigator = document.CreateNavigator();


        XmlNamespaceManager man = new XmlNamespaceManager(navigator.NameTable);
        man.AddNamespace("bk1", "http://www.contoso.com/books");
        XPathExpression query = navigator.Compile("/bk1:bookstore/bk1:book/bk1:title");

       query.SetContext(man);
        // Select all books authored by Melville.
        //XPathNodeIterator nodes = navigator.Select("descendant::book:book[book:author/last-name='Melville']",man);
      //  string query="/bk:bookstore/bk:book/bk:title";
        XPathNodeIterator nodes = navigator.Select(query);
       
        while (nodes.MoveNext())
        {
            // Clone the navigator returned by the Current property. 
            // Use the cloned navigator to get the title element.
            XPathNavigator clone = nodes.Current.Clone();
            clone.MoveToFirstChild();
           
           Response.Write(string.Format("Book title: {0}", clone.Value));
           Response.Write("<Br>");
        }