While nearly completing a new release, we’ve ignored the large size of the XML data that our WCF service returns to our silverlight client. Now we’re investigating how to shrink the data, so that the results aren’t in the 10-100mb range.
Its seems clear that binary serialization is the solution, and it seems easy enough to serialize the data into binary with, for instance, SharpSerializer, but through all of the SO posts about binary serialization and other tutorials I’ve come across, no one addresses how to send the serialized data across the wire to the Client. I expect I’m missing some obvious but critical piece to the WCF service puzzle.
Hopefully someone can lend me some help. Let me know if I should include more information.
First, try the built-in binary encoding (<binaryMessageEncoding> in config, see http://www.mostlydevelopers.com/blog/post/2009/10/14/Silverlight-3-WCF-Binary-Message-Encoding.aspx and http://www.silverlight.net/learn/data-networking/network-services-(soap,-rest-and-more)/how-do-i-use-binary-encoding-for-wcf-with-silverlight-3 ).
Your data will probably shrink, but please note that the built-in binary encoding was designed to be as fast as possible, not as small as possible.
If that’s not enough and you want to use a 3rd=party component to do the serialization to binary data, you can indeed return this data as a byte[] (but you will also need to use <binaryMessageEncoding> above to prevent WCF from base64-encoding the data to make it valid XML). You can also use Stream instead of byte[], this won’t give you true streaming behavior on the Silverlight client side but can give you true streaming on the server side.