XmlDocument Constructor

using System;
using System.Xml;
using System.Xml.Schema;

namespace Microsoft.Samples.Xml
{
    sealed class XmlDocumentSample
    {
        private XmlDocumentSample() { }

        static XmlReader reader;
        static String filename = "bookdtd.xml";

        public static void Main()
        {

            ValidationEventHandler eventHandler = new ValidationEventHandler(XmlDocumentSample.ValidationCallback);

            try
            {
                // Create the validating reader and specify DTD validation.
                XmlReaderSettings settings = new XmlReaderSettings();
                settings.DtdProcessing = DtdProcessing.Parse;
                settings.ValidationType = ValidationType.DTD;
                settings.ValidationEventHandler += eventHandler;

                reader = XmlReader.Create(filename, settings);

                // Pass the validating reader to the XML document. 
                // Validation fails due to an undefined attribute, but the  
                // data is still loaded into the document.
                XmlDocument doc = new XmlDocument();
                doc.Load(reader);
                Console.WriteLine(doc.OuterXml);
            }
            finally
            {
                if (reader != null)
                    reader.Close();
            }
        }

        // Display the validation error. 
        private static void ValidationCallback(object sender, ValidationEventArgs args)
        {
            Console.WriteLine("Validation error loading: {0}", filename);
            Console.WriteLine(args.Message);
        }
    }
}

<!DOCTYPE bookstore [
  <!ELEMENT bookstore (book)*> 
  <!ELEMENT book (title,author,price)>
  <!ATTLIST book genre CDATA #REQUIRED>
  <!ELEMENT title (#PCDATA)>
  <!ELEMENT author (#PCDATA)>
  <!ELEMENT price (#PCDATA)>]>
<bookstore>
  <book genre="fantasy"  ISBN="2-3631-4">
    <title>Oberon's Legacy</title>
    <author>Corets, Eva</author>
    <price>5.95</price>
  </book>
</bookstore>