xmlValidating reader and stream vs. file

[John Hopper]

I pass an xmlDocument to my web service. There I want to use an xmlValidating
reader for validation of that document. I do not want to create a file, but
rather validate from a stream. My schema document specifies a boolean for an
element where, in the instance document, there is the value "2222".

The code:

(1)

Dim buf As Byte() = System.Text.UTF 8Encoding.UTF8. GetBytes(oRepor t.OuterXml)
Dim ms As New MemoryStream(bu f)
ms.Position = 0
tr = New XmlTextReader(m s)

--

I have also tried

(1a)

Dim myStream As System.IO.Strin gReader
myStream = New System.IO.Strin gReader(oReport .OuterXml.ToStr ing)
tr = New XmlTextReader(m yStream)

(1b)

Dim myStream As System.IO.Strin gReader
myStream = New System.IO.Strin gReader(oReport .OuterXml.ToStr ing)
tr = New XmlTextReader(m yStream)
tr.Read()

(1c)

tr = New XmlTextReader(" C:\inetpub\wwwr oot\mc\ws050523 .1\file.xml")

(1d)

tr = New XmlTextReader(" C:\inetpub\wwwr oot\mc\ws050523 .1\file.xml")
tr.Read()

--

(2)

vr = New XmlValidatingRe ader(tr)
AddHandler vr.ValidationEv entHandler, AddressOf ValidationCallB ack

Dim schema As String = "urn:mysche ma-schema"
Dim xsc As New XmlSchemaCollec tion
xsc.Add(schema, "C:\inetpub\www root\mc\ws05052 3.1\myschema.xs d")
vr.Schemas.Add( xsc)

While vr.Read()

End While

....

I can step through the proxy class created from the web service and using
vr.ReadString I see the values being read from either the file or from the
stream.

Using 2 with

(1) --> The expected validation exception is Not raised.
(1a) --> is Not raised.
(1b) --> is Not
(1c) --> is
(1d) --> is Not

Can anyone help me understand these results and why I can't use 1 & 2 to
validate the xmlDocument in the web service?
Thank you,

John Hopper