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From: Chris Morse on 26 Jan 2010 09:46
Hi,

This is a strange problem for me, because I know this was working
correctly, but now when I am testing it, it is not working. Nothing
changed in my code, it merely acts now as if I have not set
"HttpWebRequest.AllowWriteStreamBuffering = False" and all data is
sent quickly (ie, buffered locally). The whole point of turning off
the buffering is so that I can provide a progress bar for larger
uploads.

Here is the basic code:

Dim H As HttpWebRequest = HttpWebRequest.Create(szRequestURL)
H.ContentType = "application/octet-stream"
H.Method = "POST"
H.Timeout = nTimeoutSec * 1000
H.AllowWriteStreamBuffering = False
H.ContentLength = FI.Length

Dim S As Stream = H.GetRequestStream()

Dim timeStart As DateTime = DateTime.Now
Dim TS As TimeSpan

Dim nRead As Integer
Dim BUFFER(4096) As Byte
Dim nBytesSent As Integer = 0

Me.ProgressBar1.Minimum = 0
Me.ProgressBar1.Maximum = CInt(FI.Length)
Me.ProgressBar1.Value = 0

Do
nRead = myStreamReader.Read(BUFFER, 0, 4096)
If nRead > 0 Then
S.Write(BUFFER, 0, nRead)
'S.Flush()
nBytesSent += nRead
Me.ProgressBar1.Value = nBytesSent
Application.DoEvents()
Else
Exit Do 'All data sent successfully
End If
Loop

myStreamReader.Close()
myStreamReader = Nothing


I have done google searches and checked MSDN and everything seems to
be correct in the code. Also, I know I had this working before, it
used to send data slowly (my internet connection has a max upload
speed of about 50KB/sec, so it takes a good 20 seconds to upload
1MB). Now a 5MB upload is completed in under 0.03 seconds, and, after
the code above, the code hangs on the following line - while the
uploads is actually completed.

Dim WR As HttpWebResponse = CType(H.GetResponse(),
HttpWebResponse)

There is no authentication or redirections required, and I don't get
any exceptions thrown. It simply acts as if I never issued the
"H.AllowWriteStreamBuffering = False" call.

Any ideas on what could be amiss?

By the way-- This code is running under .NET 1.1 and VS2003.

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