Question

According to the following guide at MSDN, any operations that use streamed transfers can only have one input/output parameter.

Link: http://msdn.microsoft.com/en-us/library/ms731913.aspx (see heading “Restrictions on Streamed Transfers”)

I’m using streamed transfers for a WCF service that lets clients/consumers upload files to it. The upload itself works fine, but I need a way of passing two more input parameters along with the Stream object: ‘string filename’ and ‘int userid’.

How would I go about doing this?

Answer 1

There´s something called headers that you can use in your datacontract:

Example of the interface:

[ServiceContract]
public interface IFile
{
   [OperationContract]
   Stream DownloadFile(int fileid);

   [OperationContract]
   bool UploadFile(FileUploadMessage request);
}

Put this in a separate file:

[MessageContract]
public class FileUploadMessage
{
[MessageHeader(MustUnderstand = true)]
public int MyInt {get;set;

[MessageHeader(MustUnderstand = true)]
public string MyString {get;set;

[MessageBodyMember(Order = 1)]
public System.IO.Stream FileByteStream {get;set;}
}