using (FileStream stream = File.OpenRead(xsdFilepath))
{
    XmlReaderSettings settings = new XmlReaderSettings();

    XmlSchema schema = XmlSchema.Read(stream, OnXsdSyntaxError);
    settings.ValidationType = ValidationType.Schema;
    settings.Schemas.Add(schema);
    settings.ValidationEventHandler += OnXmlSyntaxError;

    using (XmlReader validator = XmlReader.Create(xmlPath, settings))
    {
        // Validate the entire xml file
        while (validator.Read()) ;
    }
}
// The OnXmlSyntaxError function will be called when a syntax error occur.