See how using "Prism" and it's friend Unity (an implementation of IoC) from the Patterns and Practices team can help in building Silverlight applications in a way that lends itself to testability and modularity.

1. Use (a) Prism for your development Learn how to build highly composableapplications 12/21/2009 1

2. KonstantinosPantos http://blog.pantos.name http://twitter.com/kpantos 12/21/2009 2

3. Prism Composite Application Guidance Patterns and Practices Group Targets Silverlight and WPF Can be used for other kind off applications Documentation Libraries Source Code Default IoC - Dependency injection mechanism Can use others Windsor Castle etc. 12/21/2009 3

4. Unity IoC Inversion of Control “Container” Register Implementations Lookup based on Interfaces Dependency Injection 12/21/2009 4

5. Demo 1 Inversion of Control – Dependency Injection 12/21/2009 5

6. Using Unity Pros Loosely coupled software Cons Independent libraries Deployment Have to put the libraries in the right folder at the right time. Fusion resolution What if I want to Load types from disk, web site, etc What if I want to Load types on Demand Assemblies’ dependencies Registration ordering matters have to know the registration order. What happens for hundreds of assemblies? 12/21/2009 6

7. Prism to the rescue Modularity List / Catalog / Set Modules Dependencies on other modules Flexibly loaded File System, Web, XAP Delay Loaded (i.e. only load on demand) Module self - initialization 12/21/2009 7

8. Demo 2 Modularity - Prism 12/21/2009 8

9. Using Prism Quite a bit of Code IServiceLocator UnityContainer IModuleInitilizer IModuleCatalog IModuleManager Bootstrappersolves all that! 12/21/2009 9

10. Demo 3 Bootstrapper 12/21/2009 10

11. Prism in Silverlight Coming Next Most elaborate Hello World application Shells, Regions, Views Commands Event Aggregation Region Context 12/21/2009 11

12. Demo 4 Most elaborate Hello World! application 12/21/2009 12

13. Stuff Unityhttp://www.codeplex.com/Unity Prism http://www.codeplex.com/Prism ServiceLocatorhttp://msdn.microsoft.com/en-us/library/dd464679(VS.85).aspx Patterns and Practiceshttp://msdn.microsoft.com/en-us/practices/default.aspx 12/21/2009 13

14. Thank you 12/21/2009 14