An Introduction to the Model-View-ViewModel Pattern rakeshk@damcogroup.com rakesh308@gmail.com

WPF Intoduced in 3Framework 3.0. XAML UI Language. Vector Based rendering. Rich Composition ……………. TWO WAY DATABINDING

What is MVVM? Model View ViewModel

Standing on the Shoulders of Giants MVC MVP Martin Fowler Josh Smith John Gossman Sean Wildermuth

Why MVVM? Separation Of Concerns Test Driven Approach Code Cleanliness & Modular Approach Support WPF two way Data binding feature.

How Do We Achieve that? View ViewModel Model

DONOT FOLLOW THIS View View View ViewModel Model

A More Complete Diagram Unit Tests Integration Tests View XAML, Code Behind Bindings Behavior Actions ViewModel Properties, Commands, View Logic Data Events Model Service Proxies Web

DEMO – SAMPLE

MVVM Guidelines 1. Reduce or eliminate your code-behind 2. Bind all of your UI inputs/outputs to your ViewModel 3. Implement INotifyPropertyChanged on your ViewModel 4. When testing, treat ViewModel as the Real UI 5. Avoid events. Use commands instead

Third Party Support Prism MVVM Light Caliburn Silverlight FX