OCT 31 Webinar Slides

2. Getting Started
with MVVM in
(WPF / Silverlight)
NISHANTH ANIL
TECHNICAL EVANGELIST
@nishanil | nanil@infragistics.com | nnish.com
facebook.com/InfragisticsIndia

3. Agenda
– Patterns
– What’s MVVM?
– Foundation (WPF concepts)
– Available Frameworks
– Your First ViewModel (demo)
– Simple Dashboard (demo)
@nishanil

4. Patterns – are guidelines not rules!
• UI patterns
– Model – View – Controller
– Model – View – Presenter
– Presentation Model
– Model – View – ViewModel
• Why do they exist?
– Separation of concerns
– Testability
– Maintainability
@nishanil

5. MVVM
@nishanil

6. Foundation – WPF Concepts
• INotifyPropertyChanged/INotifyCollectionChanged
• DataContext
• DataBinding
• Commanding
@nishanil

7. Foundation – WPF Concepts
• INotifyPropertyChanged
– Not a WPF only concept (part of an implementation of GOF Observer pattern)
• Observer Pattern in brief: When one object changes state, all its dependents are notified and updated automatically.
– Implement INotifyPropertyChanged in your ViewModels
– And Notify when property changes
• INotifyCollectionChanged
– Similar to INotifyProperyChanged, but it applies to collections of objects
– Use ObservableCollection<T> instead of manually implementing
@nishanil

8. Foundation – WPF Concepts
• DataBinding
– A View binds to properties on a ViewModel
• DataContext
– Set ViewModel to the DataContext of the View
– This property is meant to be set to the data object it visualizes.
@nishanil

9. Foundation – WPF Concepts
• Commanding
– Is an input mechanism
– Without command MVVM will be less powerful
– Commands in WPF are implemented using ICommand interface
ICommand Implementation
ViewModel
Binding the command in the View
@nishanil

10. Available Frameworks
Source: Wikipedia, As on 31st OCT 2012 @nishanil

11. Some helper files
• MVVM Foundation
– http://mvvmfoundation.codeplex.com/
– ObservableObject Class
– RelayCommand
@nishanil

12. Demo
• Writing your first ViewModel
• A simple Sales dashboard
@nishanil

13. Silverlight: MVVM + RIA
@nishanil

14. Resources
• Introduction to Model/View/ViewModel pattern for building
WPF apps (John Gossman)
– http://blogs.msdn.com/b/johngossman/archive/2005/10/08/478683.a
spx
• WPF Apps With The Model-View-ViewModel Design Pattern
(Josh Smith)
– http://msdn.microsoft.com/en-us/magazine/dd419663.aspx
• Infragistics Community –
http://www.infragistics.com/community/blogs/
• Infragistics WPF Products -
http://www.infragistics.com/products/wpf/
• Infragistics Silverlight Products -
http://www.infragistics.com/products/silverlight/
@nishanil

15. Q&A
NISHANTH ANIL
TECHNICAL EVANGELIST
@nishanil | nanil@infragistics.com | nnish.com
facebook.com/InfragisticsIndia