A walkthrough of the fundamentals of Model-View-ViewModel (MVVM).

1. Introduction to MVVM
Jeremy Likness
Senior Consultant, Project Manager
Twitter: @JeremyLikness
Blog: http://csharperimage.jeremylikness.com/
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2. what we do
consulting training debugging
who we are
Founded by top experts on Microsoft – Jeffrey Richter, Jeff Prosise, and John Robbins –
we pull out all the stops to help our customers achieve their goals through advanced
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how we do it
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• Architecture, analysis, and design services • On-site instructor-led training
• Full lifecycle custom software development • Virtual instructor-led training
• Content creation • Devscovery conferences
• Project management
• Debugging & performance tuning
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3. Agenda
• What is MVVM?
• Why use MVVM?
• MVVM Frameworks Overview
• What is the Cost?
• Demo
• MVVM Prescription
• Questions
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4. What is MVVM?
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5. What is MVVM?
• Do you ever have to start work on an application before the
design team is ready?
• Do you make updates in parallel with the design team?
• Do you unit test your solutions?
• Do you reuse code and components both within and across
projects?
• Do you ever have to change the user interface, and wouldn’t
it be nice to do it without having to hit your code as well?
• MVVM solves these types of problems!
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6. What is MVVM? The Model
• Domain object
• Data/Information and/or Behavior
• Possible persistence information (id, GUID, etc)
• Separate from “how it got there”
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7. What is MVVM? The View
• What the user “sees” / experiences
• User-friendly format for presentation
• Multiple inputs (gestures)
• Behaviors
• Events
• Data-bindings
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8. What is MVVM? The View Model
• The “controller”
• Doesn’t know about the view
• Exposes methods and commands
• Coordinates with services
• “Owns” models, and knows how to retrieve/update them
• Might be used in multiple views
• Can communicate with other view models
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9. What is MVVM? The View Model
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10. 10 Reasons to Use MVVM
1. Separation of concerns/de-coupling.
2. Designer/developer workflow.
3. Unit testing.
4. Data-binding.
5. Code reuse.
6. Modularity.
7. Refactoring containment.
8. Extensibility.
9. Tools support (Windows Phone 7, MVVM Light, etc.)
10.Pattern vocabulary.
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11. MVVM Frameworks
1. PRISM (Guidance/Quickstart).
2. MVVM Light.
3. Caliburn.
4. Cinch.
5. nRoute.
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12. How Much Does it Cost?
• Learning Curve (Developers)
• Bigger down payment (architecture, infrastructure)
- Low interest rates and minimum monthly payments!
• Visibility (de-coupling can backfire)
• Duplication of code (e.g. WCF RIA)
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13. demo
MVVM “Before and After”
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14. MVVM Framework Prescription
1. View management.
2. View and view-model routing.
3. INotifyPropertyChanged.
4. IDataErrorInfo.
5. ICommand (UObey)
6. Dialogs.
7. Messaging.
8. Navigation.
9. Services.
10.Unit testing.
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15. Questions?
Jeremy Likness
Senior Consultant, Project Manager
Twitter: @JeremyLikness
Blog: http://csharperimage.jeremylikness.com/
consulting training debugging wintellect.com