The Basics - II

Silverlight and JS DemoMVVMBindingChange Notification

• INotifyPropertyChanged

• Dependency Properties

• ObservableCollection

XAMLSilverlight and Web ServicesRIA ServicesDemos

Model – Domain Object• Actual Data

• Holds information, not behavior or services that

manipulate the information

View Model – converter between View and

Model

View – Presentation

Separation between View and ViewModel

Test driven development

Better data binding - two way data-binding

possible

ViewModel can aggregate parts of model

present in separate classes

One Way• GUI element is updated whenever the object to

which element is bound is updated

Two Way• GUI element is updated whenever the object to

which element is bound is updated. Also, object is

updated whenever GUI changes.

One Time• The object to which the UI element is bound can

change the value of GUI element only once.

INotifyPropertyChanged

Dependency Properties

Button 1

Button 2

Button 3

Grid.Column = 0

Shared Default Value

Grid.Column = 1Button 4

Instance Specific Value

Separating Design from Development

Portability between Web and Windows• Logical Tree – XAML as is

• Visual Tree – representation of actual code

Every element of visual tree is a dependency property

Demo

Demo

Simplifies development of N-tier RIA

No need to focus on service plumbing

Client is automatically updated with latest

logic every time the solution is re-compiled

Demo