How to transfer large amount of data using WCF?

Question

We are currently trying to move large amounts of data to a Silverlight 3 client using WCF with PollingDuplex. I have read about the MultiplerMessagesPerPoll in Silverlight 4 and it appears to be quite a bit faster. Are there any examples out there for me to reference (using MultipleMessagesPerPoll)? Or maybe some good references on using Net.TCP? Maybe I should be taking a completely different approach? Any ideas or suggestions would be greatly appreciated.

Thanks!

Answer 1

Streaming serialized response chunks works well:

Your WCF binding configuration would resemble the following:

<binding name="myCustomBinding">
   <binaryMessageEncoding />
   <httpTransport transferMode="StreamedResponse" 
                  maxBufferSize="2147483647" 
                  maxBufferPoolSize="2147483647" 
                  maxReceivedMessageSize="2147483647" />
</binding>

Your Service method would look something like:

[OperationContract]
public Stream GetDataStream(string objectId)
{
   Stream stream = new MemoryStream();

   MyObject obj = Manager.GetObject(objectId);

   DataContractSerializer serilizer = new DataContractSerializer(typeof(MyObject));

   serilizer.WriteObject(stream, obj);

   stream.Position = 0;

   return stream;
}

And your client-side completed method would do something like:

static void client_GetDataStreamCompleted(object sender, GetDataStreamCompletedEventArgs e)
{
   if (e.Error == null)
   {
      DataContractSerializer serializer = new DataContractSerializer(typeof(MyObject));

      MyObject obj = serializer.ReadObject(new MemoryStream(e.Result)) as MyObject;
   }
}