Prevent NetworkCredenti al caching

[steve]

Hi

We have an application that send webRequests to a server using a specified
user accounts. These requests will often be for different users.

The problem we have is that the webRequest, even though it is a fresh object
that is disposed of, will always use the first newtowrkCrednti al we specify.
We are NOT using credentialCache as we dont want to cache the credentials.
Anyone know why this is and how to prevent / workaround this?

public sub test()

messageBox.Show (sendData("www. test.com/returnData.asp" ,"userA","passw ord",false,noth ing))

messageBox.Show (sendData("www. test.com/returnData.asp" ,"userB","passw ord",false,noth ing))

messageBox.Show (sendData("www. test.com/returnData.asp" ,"userC","passw ord",false,noth ing))
end sub

public function sendData(ByVal strUrl As String, ByVal strUser As String,
ByVal strPwd As String, ByVal blnPost As Boolean, ByVal strToSend As String)
as string
Dim webReader As System.IO.Strea mReader
Dim strResp As String
webReader = New System.IO.Strea mReader(streamP ostXML(strUrl,
strUser, strPwd, blnPost, strToSend))
strResp = webReader.ReadT oEnd()
return strResp
end function

Public Shared Function streamPostXML(B yVal strUrl As String, ByVal strUser
As String, ByVal strPwd As String, ByVal blnPost As Boolean, ByVal strToSend
As String) As System.io.Strea m
Dim webReq As System.Net.WebR equest
Dim webResp As System.Net.WebR esponse
Dim cred As System.Net.Netw orkCredential
Try
webReq = System.Net.WebR equest.Create(s trUrl)
If Not strUser Is Nothing Then
cred = New System.Net.Netw orkCredential(s trUser, strPwd)
webReq.Credenti als = cred
End If
If blnPost Then
webReq.Method = "POST"
Else
webReq.Method = "GET"
End If

If Not strToSend Is Nothing And strToSend <> "" Then
Dim reqStream As System.IO.Strea m
Try
'convert string into bytes so can write to a stream
Dim bytToPost() As Byte
bytToPost = System.Text.Enc oding.UTF8.GetB ytes(strToSend)
webReq.ContentL ength = bytToPost.Lengt h
reqStream = webReq.GetReque stStream
' Write encoded data into request stream
reqStream.Write (bytToPost, 0, bytToPost.Lengt h)
Finally
reqStream.Close ()
End Try
End If
'now we get the response and pass it into a stream reader and
read it
webResp = webReq.GetRespo nse
Return webResp.GetResp onseStream
Catch ex As Exception
Throw ex
Finally
webReq = Nothing
cred = Nothing
webResp = Nothing
End Try

End Function
Code is: