2. Architecting Silverlight Applications with MVVM
Shawn Wildermuth
President
AgiliTrain
Session Code: WIA301

3. The Problem

4. The Problem (2) Tight Coupling Adds Complexity Simple Changes Cascade
Difficult to Test
Difficult to Develop Large Applications

5. Separation of Concerns
Loose Coupling
Layers are Individually Responsible
Established Patterns
Lessens the Need to Reinvent Architecture

6. Patterns Model-View-Controller Model-View-Presenter
Model-View-ViewModel

7. Patterns (2) XAML is Declarative Allows for Code-less Views
Older Patterns Don’t Fit

8. Model-View-ViewModel

9. Model-View-ViewModel (2)
Silverlight
XAML
View
C#/VB
ViewModel
Model
Internet
Server
C#/VB
Services

10. Building the MVVM
Planning on MVVM
Build in Tiers
Plan for Testing

11. Building the MVVM (2) The Model Expose Data as Collections
Expose Methods for Different Data Shaping
More than one ViewModel May Use a single Model
Build Interface Providing Data
Allows Mocking of the Database if necessary
Eliminate Tight Coupling of Services with Model

12. demo
The Model

13. Building the MVVM (4) The ViewModel Expose API that the View Needs
Use the Model to Provide the Data

14. demo
The ViewModel

15. Building the MVVM (6) The View Declarative UI
Use as Much XAML as Possible
Don’t Write Code to Rebind Data
Perfect View is Code-less
In Silverlight 3 Behaviors and Element Binding Help

16. demo
The View

17. Evolving Pattern MVVM is Still Growing
Some Frameworks Support it (e.g. Prism)
Philosophy of Specifics is not settled
View-Centric
ViewModel-Centric
Marriage/Mediator
No Completely Right/Wrong Way to Implement It
Patterns Only Good If They Help

18. Frameworks I Hand-Coded MVVM Frameworks Help
Laurent Bugnion’s Light MVVM
Nikhilk Kothari’s FX Framework
Michael Sync’s Silverlight MVVM Toolkit

19. question & answer

20. Resources www.microsoft.com/teched www.microsoft.com/learning
Sessions On-Demand & Community
Microsoft Certification & Training Resources
Resources for IT Professionals
Resources for Developers

21. Complete an evaluation on CommNet and enter to win an Xbox 360 Elite!

22. Required Slide
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