Download stream to file

Question

I have a service which provides a stream. This stream should be written to a pdf-file.

I tried this method but it didn't work:

Using hcwHandler As IHealthCareWorkerServiceHandler = Container.CurrentContainer.Resolve(Of IHealthCareWorkerServiceHandler)()
  stream = hcwHandler.DownloadPrescription(New DownloadPrescriptionRequest With {
    .ProfessionCode = ucSelectProfession.ProfessionCode,
    .RizivNumber = ucSelectProfession.Nihdi,
    .Culture = language
  }).Result
End Using

Dim buffer As Byte() = Encoding.ASCII.GetBytes(stream.ToString())

Using ms As New MemoryStream(buffer)
  'write to file
  Using file As New FileStream("prescription.pdf", FileMode.Create, FileAccess.Write)
    ms.WriteTo(file)
  End Using
End Using

I have tried several other solutions as well, but none seemed to work. I never get a file.

Can anyone help me?

Put a breakpoint on this line `Dim file As New FileStream("prescription.pdf", FileMode.Create, FileAccess.Write)` to ensure it is reached. — preciousbetine, Nov 18 '19 at 09:51
@preciousbetine the line is reached. So that is not the problem. — Bart Schelkens, Nov 18 '19 at 09:52
The file should be in your current folder. Where are you checking for the file? — preciousbetine, Nov 18 '19 at 09:58
@BartSchelkens 1) Just so you know, if the binary data of the PDF is processed as a string (e.g. with `stream.ToString()`) then it will be corrupted, and `Encoding.ASCII.GetBytes` will corrupt it even more. 2) Always give a full path to a file so that you know where it is. — Andrew Morton, Nov 18 '19 at 10:45
@AndrewMorton And how can I download the pdf from the stream then? I have the file but it cannot be read. — Bart Schelkens, Nov 18 '19 at 10:46
@BartSchelkens The method is shown in [How do I save a stream to a file in C#?](https://stackoverflow.com/q/411592/1115360). — Andrew Morton, Nov 18 '19 at 10:49
@BartSchelkens What is the declaration of `stream`? Is it something which does not have a [.CopyTo](https://learn.microsoft.com/en-us/dotnet/api/system.io.stream.copyto?view=netframework-4.8) method? — Andrew Morton, Nov 18 '19 at 13:53
@AndrewMorton It has a copyto-method. It is declared as a System.IO.Stream — Bart Schelkens, Nov 18 '19 at 14:10
I have succeeded in downloading the file. But I want to display a message to the user that the file was downloaded and where. — Bart Schelkens, Nov 18 '19 at 14:42

score 0 · Answer 1 · edited Nov 18 '19 at 13:32

0

You can read the buffer (if there is data there) in a Using block without MemoryStream (like code below shows) and put a full absolute path like C:\Documents\PdfFolder\prescription.pdf

Using saveFileDialog1 As New SaveFileDialog()
  saveFileDialog1.InitialDirectory = "C:\Documents"
  saveFileDialog1.RestoreDirectory = True
  saveFileDialog1.Filter = "PDF files|*.pdf" ' change here for csv or xls
  saveFileDialog1.FileName = "yourDefaultfileName.pdf"

  If saveFileDialog1.ShowDialog <> Windows.Forms.DialogResult.Cancel Then
    If Len(saveFileDialog1.FileName.Length) > 0 Then
      Try
        Dim pdfPath As String = System.IO.Path.GetFullPath(saveFileDialog1.FileName)

        Using file As New FileStream(pdfPath, FileMode.Create, FileAccess.Write)
          file.Write(buffer, 0, buffer.Length)
        End Using

        MessageBox.Show("Saved in " & pdfPath)

      Catch
        MsgBox("Not a valid name file.")

      End Try
    End If
  End If
End Using

edited Nov 18 '19 at 13:32

InteXX

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answered Nov 18 '19 at 10:40

G3nt_M3caj

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Usually when you download something in the browser, you can see that (in Google Chrome) at the bottom of the browser. How can I do that with the file I'm writing? I can find the file now, so it is being written. – Bart Schelkens Nov 18 '19 at 10:45
And remember what @Andrew Morton says about file corruption. You need to treat stream directly/in another way – G3nt_M3caj Nov 18 '19 at 10:55
@G3nt_M3caj Perhaps you could convert the C# code from [How do I save a stream to a file in C#?](https://stackoverflow.com/q/411592/1115360) into VB.NET for the OP too, to make a complete answer ;) – Andrew Morton Nov 18 '19 at 11:03
Yes, done. I hope OP understand "yourStreamHere" in this case must to be a Stream (her stream) and not a path :). – G3nt_M3caj Nov 18 '19 at 11:20

score 0 · Answer 2 · edited Nov 18 '19 at 13:39

0

And here a VB.NET version of How do I save a stream to a file in C#

Using fromWebFileStream As Stream = New StreamReader(yourStreamHere)
  Using localFileStream As FileStream = File.Create("C:\Documents\PathTo\File")
    'if you aren't at the begin of your stream uncomment this
    'fromWebFileStream.Seek(0, SeekOrigin.Begin)
    fromWebFileStream.CopyTo(localFileStream)
  End Using
End Using

edited Nov 18 '19 at 13:39

InteXX

6,135
6
43
80

answered Nov 18 '19 at 11:16

G3nt_M3caj

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I get the exception : "specified method is not supported" on the fromWebFileStream.Seek – Bart Schelkens Nov 18 '19 at 11:43
If you are at the start of your stream you can remove Seek method. I update the code, sorry I was distracted :) – G3nt_M3caj Nov 18 '19 at 12:46

Download stream to file

2 Answers2