Yesterday’s Code Camp presentation went relatively well – the Demo Gods only frowned a couple of times. I wanted to take a few moments to review some of the things that went wrong, what I did to overcome them, and also to review some of the questions I was asked to answer.

There’s a lot that goes into making a decision about adopting a technology for a problem, especially if it is for a client. Silverlight is certainly a good platform for developing interesting applications, including Line of Business applications. I’d invite people to review the “Why Silverlight” portion of my presentation to see if its benefits are applicable to their specific situations.

Issue: Visual Studio and IE locked up during the demo. I was running the application, and it got stuck at 45% loading. IE was unresponsive and Visual Studio told me it was busy whenever I tried to do anything.
Cause: Voodoo?
Resolution: I used Task Manager (actually I used Process Explorer) to kill IE. Visual Studio was still locked up. I tried to shut down the Cassini web host, but the tray icon was unresponsive. In the interests of time, my next step involved using Process Monitor to kill Visual Studio and just restarted things from where I left off. That worked…otherwise my next steps would have involved rebooting, and perhaps doing a clean build.

Issue: During the Authentication topic, checking the ASP.Net Authentication Service revealed that it was in a bad state.
Cause: Pilot-error (cut and paste problem in the web.config)
Resolution: When I pasted in the configuration contents for the Authentication and Role services, I neglected to combine these with the pre-existing service configuration for the other web service I was using. The configuration parser got annoyed when it realized that I had two sections with the same name. I just merged the Service and Behavior declarations in and successfully rechecked the ASP.Net Authentication Service.

Issue: During the Authentication topic, when showing server-side role checking, I got an exception when launching the application.
Cause: Pilot-error (cut and paste problem when adding the functionality to the web service code)
Resolution: An astute attendee noticed that when I pasted my new GetProducts method into my web service code, I had left the OperationContract attribute off. I re-added the attribute, recompiled, and was able to show that logging in as different users with different roles returned different data. In gratitude, the user got one of my giveaways on the spot – a copy of O’Reilly’s Programming EF.

Question: I have a shop of ASP.Net/HTML/Javascript developers. Should I go back and tell them that they need to learn Silverlight?
Answer: Um…yes? Again, a lot depends on the specific problem domain. Silverlight has many benefits, and if those benefits seem to apply to the direction your business is going, then it is likely that it would be a good thing to learn. Be careful, however of the old adage “if all you have is a hammer, the whole world looks like a nail.” Sometimes, you really should use a screwdriver. Silverlight is a viable technology, and is being used in many professional scenarios. Unfortunately in answering this I think I gave too many examples of people using the media capabilities of Silverlight (NBC Olympics, CNN Inauguration, etc.) For a showcase of hundreds of actual Silverlight Business applications, please visit the Microsoft Silverlight Showcase and select “Business Applications” from the Category section. Also, Microsoft has put together some compelling data in this application.

Silverlight Showcase Business Applications

There were also a couple of questions about LINQ-to-Entity and EF vs LINQ-to-SQL. There are better sources than me for information on that battle.

Spring is here (finally!) so it is time to go camping again – or perhaps at least the geek alternative. I’m doing another Code Camp, this time reprising my Silverlight for Business Applications presentation, with a few changes. It will be interesting to do this one considering everything that was just announced for Silverlight 3.0 (all of this is how you do it today, but if you wait until the new framework comes out, it will be a whole lot easier…)

Anyway, I have uploaded the presentation slide deck, materials, and my “script PDF.” The content is available for download here.

Note: I am posting this early, before I do my presentation, and will refine it later on today…I just don’t want to get into one of those “life happens” situations and neglect to push up the content in a timely manner…

The first of the New Hampshire Code Camp
Silverlight Demo content has been uploaded. The content includes the simple “Hello World” code, which is just a basic Silverlight page and project, as well as the associated auto-generated Web Project. The second project is the data access demo, which illustrates a data access layer (Linq to SQL), a WCF Service which provides access to the data access layer and returns a shaped version of the data in the DAL, and a Silverlight page which shows the data in a DataGrid.

The Silverlight page in the Data Demo also illustrates the use of the Silverlight Controls’
AutoCompleteBox to do client-side filtering of the retrieved data, as well as a Line Graph from the same library. One thing that has been added since the demo is a “swinging gate” technique to use an AutoResetEvent and a background thread to load the data for the graph, in order to avoid the latency seen in the UI when the graph was being arranged inline with keyboard entry in the AutoComplete box.  The DataDemo relies on the Products table in the AdventureWorks sample database, which can be downloaded here.  As I was using a named instance of SQL Server on my machine, some updates to the connection string may be necessary – the connection string is being kept in the web project’s web.config. file.

Also uploaded are the PowerPoint slide deck and a folder of links and slides which served as reference material used in preparing the presentation. (Near) future uploads will include the use of the ASP.Net Authentication Service from a Silverlight control, and interacting with HTML content (and jQuery) through the HTML bridge. Also in a subsequent upload will be interactive PDFs of the script content I used through the presentation.

To everyone (anyone?) who was waiting for this content, thank you for your patience.

The content is available here.