The document discusses the Model-View-ViewModel (MVVM) pattern, which is a variation of the Model-View-Controller pattern that has been popular for user interface programming. MVVM was introduced by John Gossman and takes advantage of WPF's data binding infrastructure to separate application logic and user interface. It allows testing view models independently of views and supports a smooth designer/developer workflow. View models expose command objects to handle user input and implement INotifyPropertyChanged to update bound views when properties change.

1. Binu Bhasuran
Microsoft MVP Visual C#
Facebook http://facebook.com/codeno47
Blog http://proxdev.com/

2. What is a MVVM?
How it is important to software development?

3. The Model-View-Presenter (MVP) pattern has
enjoyed popularity on various UI programming
platforms.
MVP is a variation of the Model-View-Controller
pattern, which has been around for decades.

4. Martin Fowler published an article about a
pattern named Presentation Model (PM).
John Gossman, currently one of the WPF and
Silverlight Architects at Microsoft, unveiled the
Model-View-ViewModel (MVVM) pattern

5. The single most important aspect of WPF that
makes MVVM a great pattern to use is the data
binding infrastructure.
Entirely remove the need for writing code in a
ViewModel that directly updates a view.
Can easily write code that tests
Visual designers, using MVVM makes it much easier
to create a smooth designer/developer workflow.

6. ICommand objects exposed by the ViewModel
execute.
When a ViewModel exposes an instance
property of type ICommand, the command
object typically uses that ViewModel object to
get its job done.
RelayCommand is a simplified variation of the
DelegateCommand

7. Implements the INotifyPropertyChanged
interface.