<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:cn="urn:my-urn" xmlns:sql="urn:schemas-microsoft-com:mapping-schema">

            XmlReaderSettings settings = new XmlReaderSettings();
           
            settings.ProhibitDtd = false;
            settings.Schemas.Add("http://www.w3.org/2001/XMLSchema", XmlReader.Create("w3_org_2001_XMLSchema.xsd", settings));
            settings.Schemas.Add("urn:my-urn", XmlReader.Create("my-urn.xsd"));
            
            settings.ValidationType = ValidationType.Schema;
            settings.ValidationFlags |= XmlSchemaValidationFlags.ProcessInlineSchema;
            settings.ValidationFlags |= XmlSchemaValidationFlags.ReportValidationWarnings;
            settings.ValidationEventHandler += ValidationCallBack;

            XmlReader reader = XmlReader.Create("shema.xsd", settings);

            XmlDocument XmlDoc = new XmlDocument();
            XmlDoc.Load(reader);