{"id":91,"date":"2006-02-08T21:12:41","date_gmt":"2006-02-09T04:12:41","guid":{"rendered":"http:\/\/kennyw.com\/indigo\/91"},"modified":"2006-02-08T21:12:41","modified_gmt":"2006-02-09T04:12:41","slug":"large-messages-and-wcf","status":"publish","type":"post","link":"https:\/\/kennyw.com\/?p=91","title":{"rendered":"Large Messages and WCF"},"content":{"rendered":"

CLR typed objects (and buffered messages) are great for a large breadth of applications. Sometimes though, you just want to push bytes. WCF provides a convenient way of doing so with “streamed methods”.<\/p>\n

To use WCF’s “Streaming API” you write an operation with an input and\/or output of type System.IO.Stream<\/code>. Because the Stream parameter utilizes the entire body, if an input or an output (i.e. ref<\/code> parameter, out<\/code> parameter, or return value) is of type Stream<\/code> then it must be the only input\/output specified in your OperationContract<\/code>.<\/p>\n

When using a Streaming method, you need to pass in a Stream<\/code> object that provides data incrementally from its Read()<\/code> method. One common area of confusion is that your return Stream<\/code> must also be written with the Read()<\/code> method providing the data. The mental model is that the client is “reading” the return value, and not that the server is “writing” the result.<\/p>\n

Now that your operation has been architected so that it no longer requires buffering, you have to choose a binding that is compatible with moving a lot of bytes around. Yasser<\/a> wrote a nice post on this topic here<\/a>. In a nutshell you need to:<\/p>\n