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_StreamReader()
{
//strArquivoInteiro 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 strArquivoInteiro = xmlDoc.OuterXml;

byte[] byteArray = Encoding.ASCII.GetBytes(strArquivoInteiro);
MemoryStream streamXSD = new MemoryStream(byteArray);

StreamReader readerXsd = new StreamReader(streamXSD);

XmlReaderSettings settings = new XmlReaderSettings();
settings.ValidationEventHandler += this.ValidationEventHandler;

settings.ValidationType = ValidationType.Schema;
settings.Schemas.Add("schema.xsd", XmlReader.Create(readerXsd));
settings.CheckCharacters = true;

XmlReader XmlValidatingReader = XmlReader.Create(@"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, ValidationEventHandler);

XmlValidatingReader ValidatingReader = new XmlValidatingReader(Reader);

//// 6- Setar o tipo de validação para o objeto XmlValidationReader
ValidatingReader.ValidationType = ValidationType.Schema;

//// 7- Adicionar Schema a coleção de Schemas XmlValidationReader
ValidatingReader.Schemas.Add(Schema);

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

XmlValidatingReader.Read();
XmlValidatingReader.Close();

//// 8- Adicionar o endereço do ValidationEventHandler ao ValidationEventHandler do XmlValidationReader
ValidatingReader.ValidationEventHandler += ValidationEventHandler;


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

}


ValidatingReader.Close();
}
catch (Exception ex)
{
ValidatingReader.Close();
XmlValidatingReader.Close();

}
}
private void ValidationEventHandler(object sender, ValidationEventArgs args)
{
bool blnXmlValido;
if (args.Severity == XmlSeverityType.Warning)
{

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

blnXmlValido = false;
}
else if (!(string.IsNullOrEmpty(args.Exception.ToString()) ))
{

blnXmlValido = false;
}

if ((args.Exception != null))
{

}
}