Question

So I have a function which returns a pdf stream. The calling procedure gets the stream and writes it to disk (thanks ServiceGuy!). Normal VB code is as follows:

Public Function GetPDF() As System.IO.FileStream

    GetPDF = File.OpenRead("C:\Documents and Settings\jspel903\Desktop\3211LD.pdf")

End Function

Now, for whatever reason when I put that code in my WCF (see below) and build/install, it won’t return anything. The calling procedure gets nothing after My WCF is hosted in a Windows service (I can’t get it to debug or step into). So I’m wondering if, perhaps, WCFs won’t return a FileStream?

Here’s the IService:

<ServiceContract()> _
Public Interface IService1

<OperationContract()> _
Function GetPDF() As System.IO.FileStream
'Should return a .pdf file as a stream

End Interface

Here’s the svc:

Imports System.IO

Public Class Service1
Implements IService1


Public Function GetPDF() As System.IO.FileStream Implements IService1.GetPDF

    GetPDF = File.OpenRead("C:\Documents and Settings\jspel903\Desktop\3211LD.pdf")

End Function
End Class

Seems to me like it should work. Any ideas?

Answer 1

You probably want to convert your FileStream to a byte array and return that. WCF is generally limited to returning serializable types.

   // fs is your FileStream

   byte[] Data = new byte[fs.Length];

   fs.Read(Data,0,fs.Length);