This document discusses various architectural patterns and considerations for building WPF applications. It covers topics like inductive vs deductive UI, navigation patterns, presentation patterns like MVVM and MVP, UI composition, inter-view communication through events, dependency injection, partitioning applications, leveraging XAML for consistency and abstractions, and performance considerations like retained vs immediate mode rendering. The goal is to provide guidance on architecting robust and maintainable WPF applications.

1. Architecting WPF Applications Paul Stovell Senior Consultant WPF Technical Specialist Readify

3. Agenda WPF Overview Inductive vs. Deductive UI Navigation Presentation Patterns Composition Inter-view Communication Dependency Injection Partitioning Leveraging XAML Performance Considerations

4. WPF Overview

5. Unified Presentation

6. Web or Windows? Windows Intranet Internet Silverlight Windows Forms Java Java Applets ASP.NET WPF XBAP WPF AJAX

7. XBAP

8. XBAP

9. WPF Releases .NET Framework 3.0 .NET Framework 3.5 .NET Framework 3.5 Service Pack 1 .NET Framework 4.0

10. Inductive vs. Deductive

11. Deductive UI

12. Deductive UI

13. Inductive UI

14. Inductive UI

15. Inductive vs. Deductive Why does it matter? UI composition Patterns Navigation Patterns Service Layer ChangeAddress vs. SaveCustomer

16. DataGrid

17. Navigation

18. Linked List Page 1 Page 2 Page 4 Page 3

19. Centralized Decisions Navigation Handler Page 1 Page 2 Page 3 Page 4

20. Presentation Patterns

21. Presentation Patterns Model-View-ViewModel aka Presentation Model Model-View-Presenter aka Supervising Controller Model-View-Controller

22. Model View ViewModel Change Address View Model Customer Address Accounts Change Address ViewModel

23. Model View ViewModel (Wrapped) View Model Change Address View Customer VM Account VM Address VM Change Address ViewModel Model Customer Account Address

24. Model View Presenter Change Address View Model Customer IChangeAddressView Address Accounts Change Address Presenter

25. Model View Presenter with VM Change Address View Model Customer Change Address ViewModel IChangeAddressView Address Accounts Change Address Presenter State Behaviour

26. Model View Controller Controller View 1 Model 1 View 2 Nav Request Model 2 View 3 Model 3

27. Presentation Patterns Things to consider: Does every view need separated presentation? Does every view need to follow the same pattern? Code Behind isn’t Evil (DataGrids are) MVPoo

28. UI Composition

29. Model-based Composition Recent Orders ViewModel Search ViewModel Weather ViewModel Order List Search Weather

30. UI-based Composition Bottom-Up Order List Top Region 2. Place Navigation Bottom Region 1. Resolve Search Weather

31. UI-based Composition Top-Down Order List Top Region Bottom Region Search Weather

32. Inter-View Communication

33. Inter-View Communication Standard .NET events Search Model Child model raises event Parent model forwards event Results Model Criteria Model

34. Inter-View Communication Event Aggregator Results Model Criteria Model hub Publish Handle Publish Handle Advert Model Recent Searches Model

35. Event Aggregator Advantages: Automatic thread switching Weak events Hook for cross-cutting concerns

36. Dependency Injection

37. Dependency Injection

38. Partitioning

39. Partitioning Splitting partitions: By SKU By feature By team By department

40. Partitioning Managing partitions: With solutions With projects With assemblies

41. Partitioning Resolving: Hard-coded Config Discovery

42. Partitioning Also consider: Deployment and patching Inter-partition dependencies Dev time vs. build time partitioning

43. Partitioning Remember: assemblies are like water necessary for life… …but too much can kill you!

44. Leveraging XAML

45. Abstractions <Grid> <..> <Label Grid.Row="0" Grid.Column="0" Content="First Name:" Target="{Binding ElementName=FirstNameTextBox}" /> <TextBox Grid.Row="0" Grid.Column="1" Name="FirstNameTextBox" Text="{Binding Path=FirstName}" /> </Grid> <Form> <Field For="{Binding Path=FirstName}" /> <Field For="{Binding Path=LastName}" /> <Field For="{Binding Path=EmailAddress}" /> </Form>

46. Consistency <TextBlock Foreground="Red" Text="Please enter..." /> <TextBlock Foreground="{StaticResourceColor.Bad}" Text="Please enter..." />

47. Style Catalogues <TextBox Width="300" .../> <TextBox Width="156" .../> <TextBox Width="215" .../> <TextBox Style="{StaticResourceTextBox.Big}" /> <TextBox Style="{StaticResourceTextBox.Small}" /> <TextBox Style="{StaticResourceTextBox.Medium}" />

48. Behaviours Consider this: Developers don't write code; they build tools for designers

49. Performance Considerations

50. Performance Considerations Retained scene vs. Immediate Mode Virtualization (data and UI) Memory leaks Third party components Performance test from day 1

51. Q&A Links: http://www.codeplex.com/CompositeWPF http://magellan.codeplex.com http://www.galasoft.ch/mvvm/getstarted/ http://caliburn.codeplex.com Paul Stovell paul@paulstovell.com www.paulstovell.com