Richard Thomason: Microsoft TechEd (Wednesday)

Workflow communication
This session presented some low level features of WF - event handling and queuing using an asynchronous thread model. The latter means that you can't rely on your code executing in the same thread every time, and you need to create an Execute method that runs as quickly as possible. This creates significant threading issues but there are listener tools to help and you can start other processes and communicate with them. The presenter also briefly demonstrated Finite State Machine workflows, which look interesting!

Project Astoria
This project is a database tools group one, which aims to present a consistent interface to data to HTTP clients, whatever the underlying data store and whatever the client infrastructure! In order to do this, it uses standard tools already available client-side. Data is requested in either JSON or ATOM format, and you can insert, read, update and delete the data using standard POST, GET, PUT, DELETE http commands (apparently DELETE is an http command...). The framework will be known as "ADO.NET Data Service", and uses the powerful Entity Data Model available early next year as part of the LINQ query interface. There's a great demo using Silverlight on the client at www.silverlightdata.com

After lunch I looked in at a project using an add-in called bluePortal and Microsoft Expression Blend to create your own video content site. The Expression designer and the add-in worked simply together to create the site. The add-in uses standard interfaces to interact with current Microsoft browser technologies. The kit is in action at http://www.quiksilver-europe.com/default.aspx.

.Net Scaling - Interactive Session
This was a highly technical, excellent session run by a very experienced (Superbowl.com) developer which went through the big bang bullet points of running a very high volume, highly scalable ASP.NET system.

Following that was another mind-blasting on Windows Presentation Foundation and multi-threading. I was both relieved and dismayed to discover that all the familiar issues that were originally in MFC 10 years ago were still in WPF, however the good news was that WPF gives you a lot more tools to manage them. Basically the issue is that only the GUI thread should do GUI updates, and the GUI thread should never freeze. So what do you do if you have a long operation that must update the screen.