c# проверяем xml по xsd схеме

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

public class Sample {

  public static void Main() {

    XmlSchemaSet sc = new XmlSchemaSet();
    sc.Add("", "books.xsd");
    XmlReaderSettings settings = new XmlReaderSettings();
    settings.ValidationType = ValidationType.Schema;
    settings.Schemas = sc;
    settings.ValidationEventHandler += new ValidationEventHandler (ValidationCallBack);
    XmlReader reader = XmlReader.Create("booksSchemaFail.xml", settings);
    while (reader.Read());

  }

  private static void ValidationCallBack(object sender, ValidationEventArgs e) {
    Console.WriteLine("Validation Error: {0}", e.Message);
  }
}