Great valuable video and input, like always!
One question according the mvvm stuff. I like the DI and the servicelocator aproach. How would one access the ServiceLocator in the ViewModel without tight coupling?
Or would one just create an instance (ServiceLocator svl = new ServiceLocator() ) in the ViewModel.
Or does it need to be some kind of static class or Service?

Keep up the MVVM posts!

Felix

Hi Jonas,

I'm having trouble viewing any of the conference movies...any better luck on your end?

David

Hi David,

I'm no longer able to access the videos using the direct links from Marks blog. However - I am able to watch the videos using IE accessing them using the NDC Agenda page: http://ndc2009.no/agenda.aspx?cat=1071&id=1813

Good luck! :)

Hi Jonas,

You're MVVM NDC presentation was easily the best presentation I've seen on any topic. You really raised the bar for all MVVM presenters, including me.

In your presentation you brought up the PropertyChanged name in double quotes code smell.

So I took that as a challenge and found a pretty good solution that you can read here:

http://karlshifflett.wordpress.com/2009/08/01/inotifypropertychanged-how-to-remove-the-property-name-string-code-smell/

Let me know what you think.

Best to you,

Karl

Hi Karl,

And thanks for the great comment! It means allot - especially coming from you! I've been reading your blog and Code Project articles for a long time - and I have found much of your MVVM work really inspiring and interesting.

Removing code smell from PropertyChanged is one of those things anyone doing MVVM will bump into - so thanks for sharing your take on the problem :)

I've submitted this talk to TechEd Europe in November - but with 900 topic submissions (!) I guess it's going to be tough to get accepted. But keeping my fingers crossed ;)

Cheers,
Jonas

Jonas, great talk, I am in the process of trying to impliment your guidance into a test application. I am curious why you did not talk more about the Prism CAL framework. I am guessing it is because that framework is pretty heavy and you have cherry picked the things you like (Unity, Service Locator, and CompositePresentationEvent) and that is all you need. Could you explain a little on why you are not going all the way with Prism and CAL?

Thanks.
Terrence

Hie Terrance,

First off - I'm glad you liked the talk - and thanks for commenting.

When I created the talk I made a conscious decision to focus on the MVVM presentation layer design pattern and the core supporting patterns. I did not want to make this into a talk about specific frameworks like PRISM, Ninject, Unity etc.

Prism (CAL) is focusing on building composite applications and contains several features not directly related to MVVM. Things like shell, module loading and enumeration, screen region composition etc. All of these features are helpful when building a composite WPF/Silverlight application, but not directly relevant to the MVVM pattern.

Even tough the focus of the talk was on the core patterns I still wanted to use some simple implementations to be able to get through all the pieces. That's why I used the CAL implementations (but I could just as well used some other MVVM framework).

* IoC using Unity
* ServiceLocator exposing the IoC written by hand
* EventAggregator/Mediator using Event Aggregator in CAL
* ViewModel written by hand
* Commands using delegate commands in CAL

So if I where to build a new WPF/Silverlight app I would definitely evaluate Prism/CAL among other frameworks like the MVVM Light Toolkit (http://www.galasoft.ch/mvvm/getstarted/) or some of the frameworks listed on this StackOverflow question: http://stackoverflow.com/questions/1409553/what-framework-for-mvvm-should-i-use

I don't think Prism/CAL is overweighted for what it solves. But if you only want MVVM (and not modular loading, composite app support etc) then the MVVM Light Toolkit might be a good options.

Good luck, and let me know if there is anything else you're wondering about :-)

- Jonas