What’s Next for .NET Developers
An introduction to Windows 8
Windows Runtime
Metro
.NET 4.5
C# 5
Visual Studio 11
Ivan Towlson, Mindscape
Windows Evolution
XP
NT 4
NT
95
3.0
1.0
Real mode
Rudimentary shell
386 mode
Graphical shell
32-bit
Virtual memory
Pre-emptive multitasking
Explorer shell (Start)
Unified enterprise
and consumer
platforms
Windows Today
• Dominant operating system on traditional PCs
• User experience tailored to keyboard-mousemonitor setup
• Technology largely tied to x86/x64, boot from
disk
• Fundamentals of user experience largely
unchanged since Windows 95
Market Challenges
• Shifting away from traditional PCs towards
consumer devices
– Smartphones
– ‘Fondleslab’ tablets
– Media devices (audio/video, portable/home
entertainment)
– Game consoles
• Microsoft needs to compete in these markets
Design Challenges – Traditional Desktop
• Users need to be able to manage:
– Very large number of installed applications
– Lots of notifications (e.g. social media) – don’t
want to have to keep opening lots of applications
to check or catch up on different things
• Sharing silo-ed data (in apps and services)
– Most of ‘My Pictures’ may be on Facebook!
• Application distribution
Design Challenges – Devices
• Start menu is fiddly to navigate with touch
• Window management is fiddly, and in most
cases is useless overhead
• Battery life needs to be better
• Boot time needs to be near instant
• Buying an app needs to be low friction
• Keep multiple devices (including a PC) in sync
• It needs to look awesome (and harmonious)
Introducing Windows 8
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A new shell
A new set of UI standards
A new application model
A new set of APIs
– Rich visual design
– Asynchrony everywhere
– Multiple language support
• ARM support and diskless boot support
• A new set of cloud services
Introducing Visual Studio 11
• Compiler support for Windows Runtime
• Designer support for Metro
• Language changes for C#, F# and Visual Basic
– C# and VB: async
– F#: type providers
Introducing the Windows 8 Drinking Game
• “Fast and fluid” – CHUG
• “Re-imagining” – DOWN IN ONE
DO NOT PLAY THIS GAME AT TECHED
IT WILL KILL YOU
Windows Runtime
• A common runtime for Windows applications
providing a safe, object-oriented API to a
variety of services, accessible from multiple
languages
• Cripes! That sounds familiar!
WinRT Architecture
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Internally based on COM, but looks like .NET
Sandboxed
Language ‘projections’
Component-based
– Metadata format (.winmd) is very similar to .NET
• Can also be used from native code (C++)
• Windows 8 only
Diagram credit: Doug Seven
WinRT Class Library
• Mostly a subset of the .NET basic profile
– Not the full profile!
– Roughly comparable to Silverlight (plus classes for
Win8 and local machine features)
– C#/VB still target 4.5 CLR, but compiler restricts
you to APIs in the Metro profile (a la Client Profile)
• Some .NET features unavailable or moved
– Language projections take care of some changes
– Many things now in Windows.* namespaces
WinRT Class Library
• Potentially long-running APIs (e.g. file,
network) are only available in async form
– E.g. no HttpClient.Get, only HttpClient.BeginGet
– C# and VB await keyword works with WinRT
IAsyncOperation as well as CLR tasks
WinRT Application Model
• XAML-based user interface
– Very similar to Silverlight
– Styles and templates
– Data binding
WinRT Application Model
• Capabilities specified in manifest
– Services the application wants to consume
– E.g. location, camera
• Declarations specified in manifest
– Services the application offers
– E.g. file type association, search provider
• Contracts which applications can consume or
implement (e.g. search, share, picker)
WinRT Application Model
• OS suspends application when not active
– Notifications via live tile
• Non-Metro apps run on Desktop as before
– The desktop is effectively just a (special) app!
.NET 4.5
• Updates to the .NET 4.0 CLR
– Not side-by-side
• Windows 8 support
– Framework does not require Windows 8 though
• New versions of C#, VB and F#
• Many enhancements to high-level libraries
– ASP.NET, WPF, WCF, WF, MEF, ADO.NET
http://www.heikniemi.net/hardcoded/2011/10/whats-new-in-net-framework-4-5-poster/
.NET 4.5 Class Library – Selected Highlights
• BCL: async APIs using Task objects
• ASP.NET: HTML5 forms, model binders in Web
Forms, minification, AntiXSS, lots more!
• ADO.NET: Entity Framework enhancements
• WPF: ribbon control, async validation,
multithreaded collection updates, perf!
• WCF: Web Sockets, simplification!
• WF: state machines, C# expressions,
versioning enhancements, designer
Languages
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C# 5
Visual Basic… er… lost count… 11?
Visual C++ 11
F# 3
C# and Visual Basic Async
• Long running operations present a dilemma
• Synchronous:
– Pro: Clear top-to-bottom program flow
– Con: Locks up UI (and blocks other operations)
• Asynchronous:
– Pro: Fast and fluid (CHUG!)
– Con: Splits program flow, especially if you have a
sequence of async operations
• Solution: use F#
C# and Visual Basic Async
• async method modifier means method might
not complete synchronously
• Within an async method, use await keyword
to call an asynchronous method and wait for
its completion without blocking
• In an async method, you can write your code
in a top-to-bottom way and the compiler will
transform it into ‘callback style’
F# 3.0
• We doan’ need no steenkin’ async
– Because we’ve had that stuff and more for ages
– Wake me up when C# has async agents
• LINQ operators
– Okay, I admit it, that one, C# got there first
• Type providers
Visual C++ 11
• C++/CLI-like syntax that compiles to native
(COM) code targeting WinRT
– WinRT constructs like lists mapped to C++ STL
• Lots of other C++1x goodness including
lambdas which is outside the scope of this talk
– see Herb Sutter’s Build sessions for details
Building Great Metro-Style Applications
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Metro style design
Fast and fluid (CHUG!)
Snap and scale beautifully
Use the right Contracts
Invest in a great Tile
Feel connected and alive
Roam to the cloud
Embrace Metro principles
Metro Style Design
• The silhouette of a Metro style app
– Standard layouts, type sizes, etc. (as in VS
templates) – harmonious across applications
• Content before chrome
• The edge
• Comfort and touch – how people hold devices
Metro Style Design – Silhouette
Metro Style Design – Silhouette
Metro Style Design – Content Before Chrome
Metro Style Design – Content Before Chrome
Metro Style Design – The Edge
• Left and right edges are for system UI
• Top and bottom edges are for
application UI
Metro Style Design – Comfort and Touch
Building Great Metro-Style Applications
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Metro style design
Fast and fluid
Snap and scale beautifully
Use the right Contracts
Invest in a great Tile
Feel connected and alive
Roam to the cloud
Embrace Metro principles
Live Tiles
• Windows.UI.Notifications defines the available
tile templates
– E.g. plain text, text above picture, etc.
• Live tiles can show application data while
application is not running
– E.g. unread message count, stock ticker
– Your back end service sends notifications to
Windows Push Notification Service (WNS)
– WNS notifies the Windows 8 client
Building Great Metro-Style Applications
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Metro style design
Fast and fluid
Snap and scale beautifully
Use the right Contracts
Invest in a great Tile
Feel connected and alive
Roam to the cloud
Embrace Metro principles
Learn More
• Watch the videos from the Build conference
– Jensen Harris (Big Picture)
– Chris Sells (Big Picture)
– Anders Hejlsberg (C#/VB)
• Follow the ‘Building Windows 8’ blog
– http://blogs.msdn.com/b/b8/
• Download the developer preview
– Install to VHD – Hanselman has instructions
– VS11 preview for non-Metro will install on Win7
Thanks!
• Windows 8
– http://www.buildwindows.com/
– http://blogs.msdn.com/b/b8/
• Me
– http://hestia.typepad.com/flatlander/
– http://www.mindscapehq.com/
– ivan@hestia.cc
– ivan@mindscape.co.nz