How to validate, on run time, xml against xsd without save the file on local folder?

[Jimis]

I need to validate XMLs files against XSDs. The XML will be downloaded from URL and I will keep it as StremReader or XmlDocument. The XSD will return from DataBase as nvarchar(max). I am prohibited to save the files locally. Has anybody an example how to deal with this situation? I am trying this way but I am getting the XmlException "Root element is missing".


public void voltaXsd_em_Str eamReader()
{
//strArquivoIntei ro will contain the XSD comming from database as nvarchar(max) but I make simpler here.
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(@"C :\file.xsd");
string strArquivoIntei ro = xmlDoc.OuterXml ;

byte[] byteArray = Encoding.ASCII. GetBytes(strArq uivoInteiro);
MemoryStream streamXSD = new MemoryStream(by teArray);

StreamReader readerXsd = new StreamReader(st reamXSD);

XmlReaderSettin gs settings = new XmlReaderSettin gs();
settings.Valida tionEventHandle r += this.Validation EventHandler;

settings.Valida tionType = ValidationType. Schema;
settings.Schema s.Add("schema.x sd", XmlReader.Creat e(readerXsd));
settings.CheckC haracters = true;

XmlReader XmlValidatingRe ader = XmlReader.Creat e(@"C:\file.xml ", settings);

XmlTextReader Reader = new XmlTextReader(@ "file.xml") ;

XmlSchema Schema = new XmlSchema();

//Exactlly here I am getting the exception "Root element is missing" and I do not know why.

Schema = XmlSchema.Read( readerXsd, ValidationEvent Handler);

XmlValidatingRe ader ValidatingReade r = new XmlValidatingRe ader(Reader);

//// 6- Setar o tipo de validação para o objeto XmlValidationRe ader
ValidatingReade r.ValidationTyp e = ValidationType. Schema;

//// 7- Adicionar Schema a coleção de Schemas XmlValidationRe ader
ValidatingReade r.Schemas.Add(S chema);

try
{
//---------------

XmlValidatingRe ader.Read();
XmlValidatingRe ader.Close();

//// 8- Adicionar o endereço do ValidationEvent Handler ao ValidationEvent Handler do XmlValidationRe ader
ValidatingReade r.ValidationEve ntHandler += ValidationEvent Handler;


//9- Validar cada nó
while ((ValidatingRea der.Read()))
{

}


ValidatingReade r.Close();
}
catch (Exception ex)
{
ValidatingReade r.Close();
XmlValidatingRe ader.Close();

}
}
private void ValidationEvent Handler(object sender, ValidationEvent Args args)
{
bool blnXmlValido;
if (args.Severity == XmlSeverityType .Warning)
{

blnXmlValido = false;
}
else if (args.Severity == XmlSeverityType .Error)
{

blnXmlValido = false;
}
else if (!(string.IsNul lOrEmpty(args.E xception.ToStri ng())))
{

blnXmlValido = false;
}

if ((args.Exceptio n != null))
{

}
}