C# - XSD validation with has imports.

Hello,

I'm kind of new in this about XML and validation. I've got to validate lots of XML with their XSD. I use a sample from MSDN like this:

            XmlReaderSettings booksSettings = new XmlReaderSettings();

            booksSettings.ValidationType = ValidationType.Schema;
            booksSettings.Schemas.Add(null, @"C:\myfile.xsd");
            booksSettings.ValidationEventHandler += new ValidationEventHandler(booksSettingsValidationEventHandler);

            XmlReader books = XmlReader.Create(@"C:\myfile.xml", booksSettings);

            while (books.Read()) { }
            Console.WriteLine("Fin");
            Console.ReadLine();

But, the validation doesn't work because when I change or delete any tag, the validation doesn't show any errors. I thought is because myfile.xsd has an import to this:

<?xml version="1.0" encoding="UTF-8"?><xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" 
           xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
    elementFormDefault="qualified"><xs:import namespace="http://www.w3.org/2000/09/xmldsig#"
        schemaLocation="xmldsig-core-schema.xsd"/>

and has this attribute in Signature element.

<xs:element ref="ds:Signature" minOccurs="0">

I've read some posts, I've tried almost all the solutions but I can't get the validation OK. I mean, the code works but when the xsd has an imports, it doesn't work anymore. I've downloaded the xmldsig-core-schema.xsd and tried manually add to the settings.schema but it didn't work.

Any suggestion is welcome.

Best regards.

Sorry, but my english is not my first language.