mvvm appliedFrom Silverlight to Windows Phone to Windows 8

LaurentBugnionSenior Director, EuropeIdentityMine

Session Contents• A bit of recapitulation• Code code code

Disclaimer:• I am NOT a Microsoft employee and all opinions

expressed are solely my own.

a brief recap

THE MVVM PATTERN

Interactions: From MVC to MVVM

View

ViewModel

DataBinding CommandsMessages

Model

View Service

Events

PropertyChangedModel View

Controller

The MVC pattern:

Interactions: VM to View, Behaviors

BehaviourBinding

ViewModel View

Interactions: VM to View (Win8)

Binding

ViewModel View

No behaviors in Windows 8 workaround: Use properties and binding PropertyChanged event

PropertyChanged

Interactions: View Services

ViewModel ISelectFilesService

View

injection

INavigationService

injection

actionNavigationService

translating to metro

What are Metro apps, actually?

Probably not a replacement for “desktop apps”Very similar to Windows Phone appsSuspended when not in the foregroundLifetime managementRun in a sandbox, declared capabilitiesPurchased in application store

A companion for your richer application

Asynchronous

Maybe the most difficult aspectawait/async can be confusingThis is making asynchronous code easierBUT it is NOT synchronous code anyway!

Often used in Win8File system accessStream operations…

public async void Get(Uri uri){ var request = new HttpRequestMessage( HttpMethod.Post, uri); var response = await Client.SendAsync(request); var result = response.Content.ReadAsString();}

Abstract the differences

Use callbacks to async codeUse interfaces even for simple model classes

Eg: FileInfo in .NET 4 StorageFile in Windows 8

Share common classes, overload other classesExtend classes

Partial classesExtension methods

And if you have to#if WIN8

DemoMVVM in Silverlight, Windows Phone, Windows 8

Session Summary• MVVM is still the key in XAML Metro apps• Same principles, same skills as Silverlight• Design time data for the tools• Clean decoupled architecture

• Porting an app means some work and some planning!• Mostly new XAML• More asynchronous code (async/await)

call to action• Check your code for possible

asynchronous workflows• File operations• Opening streams• Use callbacks

• Check the developer preview• Stay tuned for the beta!

Be what’s next: Windows 8 Metro Apps• Find everything here

http://aka.ms/mbl-win8• Save the date! March 23: Windows 8 Developer Day

and “Nacht van Windows 8 / La Nuit de Windows 8 (app-a-thon coding night)

• Start today!• Building Windows 8 blog: http://aka.ms/mbl-win8/build• Learn with Windows 8 Dev Preview: http://aka.ms/mbl-win8/devprev • Learn about Windows Store and opportunities:

http://aka.ms/mbl-win8/store

more info athttp://blog.galasoft.ch

http://www.galasoft.ch/mvvm

@LBugnion

Q&A

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