Lots of attendees for my advanced MVVM talks at Belgium and the Netherlands. As promised, here are the demos and slides for the talks. Enjoy!

Slides

Demos

As promised, here are my session slides and demos for the “Windows 8 Store apps and the outside world” session for Visug and Windows 8 Store app user group London. Enjoy!

Slides

Demos

Since Windows 8 has been released on MSDN, many have run into problems on how to use the Enterprise version and get it to activate. As you may have noticed, during setup, you can’t enter your own key. So, how to get things to work. Follow the next simple steps and enjoy the fun of Windows 8 in full :)

1. Download Windows 8 Enterprise from MSDN. Copy your key.
2. Run the install of Windows 8. See, never during the install does it ask you for your key. Sad panda?
3. With Windows installed (read: 5 minutes later :) ), you’ll get an error if you try to activate.
4. Open an elevated prompt. To do so, go to the Start screen, search for the command prompt, right-click/top-down-swipe-to-select it and from the app bar, tap to run as administrator.
5. In the prompt, enter slmgr -ipk xxxxx-xxxxx-xxxxx-xxxxx-xxxxx (replacing all the X’s with your key obviously).
6. Activation will now work without a problem (in my case, it had activated automatically).

Now start customizing that start screen!

Last week, I was busy with another user group tour in the UK for Telerik. This year, I was able to give a total of 7 sessions in 4 cities (Hereford, Cheltenham, Bristol and Southampton). A lot of people stopped by to join me on an exploration of some Windows 8 and Windows Phone talks. During the talks, we looked at the upcoming Telerik controls for Windows 8 which will make LOB development much easier in the Windows 8 space!

Here are some of the pictures of some of the evenings:

All the slides and demos can be downloaded below.

• Hereford:
• Advanced WinRT: Slides – Demos
• Windows Phone 7.5 Background workers: Slides – Demos
• Cheltenham:
• Contract: Slides – Demos
• Tiles: Slides – Demos
• Bristol
• Visual Studio 2012 and .NET 4.5: Slides – Demos
• Southampton:
• Metro and WinRT for the Silverlight/WPF developer: Slides – Demos

Thanks for stopping by to all that attended!

For the third year in a row, I was selected as a  speaker at NDC Oslo, in my opinion one of the best developer conferences. If you're a developer, this is THE conference that should be on your agenda starting next year. All videos from this and past editions can be found at http://www.vimeo.com/ndcoslo.

This year, I was asked to do 2 sessions: Windows Phone 7.5 Background workers and Advanced WinRT. Here are all the demos and slides for both sessions:

Windows Phone 7 Background workers: Slides - Demos
Advanced WinRT: Slides - Demos

I’m very proud to officially announce that the registrations for Community Day 2012 are open. Like all the previous editions, thanks to the numerous sponsors, the event is completely free. This year, we’ve outdone ourselves: we have a 6th track, over 40 deep-technical sessions and the best networking opportunities available.

So, don’t wait to register.

Below you can find all the details of the event:

Location: Utopolis Mechelen (Map)
Address: Spuibeekstraat 5 2800 Mechelen
Event date: Thursday June 21th
Start & end time:8.30 - 19.00
Add Community Day 2012 to your agenda: Outlook *.ics file

Participating user groups:

If you’re considering buying my new book, but you’re not sure if it’s a good fit for what you’re looking, the following might help! You can now download a sample chapter where you can see the style of the book as well as get some real information!

Download the sample chapter here.

Noted the quietness on my blog? Well, it’s about to stop as I can proudly present where I’ve been spending all my free hours on: my new book: Silverlight 5 Data and Services Cookbook. This book is the sequel to my first book, Silverlight 4 Data and Services Cookbook.

The first version did very well (it’s a five-star book on Amazon UK and Amazon.com!) so we decided that the latest version of Silverlight deserved a good book in the enterprise space as well! This is why Kevin Dockx and myself wrote a whopping 650 page book.

Should you buy the second version if you already have the first edition? Well, for starters, the new book has more than 200 extra pages, all the existing recipes have been reviewed and modified for Silverlight 5. Over 35 new recipes have been added which deeply cover MVVM, RIA Services, local data and even Windows Phone 7. And of course, all the new features that come with Silverlight 5 have been added in new recipes as well! I think it’s well worth the investment!

Here’s a complete description (actually, it’s the back cover :) ):

Microsoft Silverlight is a programmable web browser plugin that enables features including animation, vector graphics, and audio-video playback – features that characterize Rich Internet Applications. However, Silverlight is a great (and growing) Line-Of-Business platform and is increasingly being used to build data-driven business applications, both in an out of the browser. It is also the heart of Windows Phone 7 development so developers can leverage their knowledge on Microsoft’s new mobile platform as well. Services enable efficient access to your data, allowing you to draw on multiple sources of data and solve particular data problems. There is very little existing material that demonstrates how to build data-driven, enterprise-ready solutions with the platform. Silverlight 3 and 4 made a big step into Line-Of-Business data services and Silverlight 5 builds further upon this.

In this book, Gill Cleeren, Microsoft Regional Director, Silverlight MVP (former ASP.NET MVP), Telerik MVP at Ordina Belgium and Kevin Dockx, a technical specialist/project leader on .NET web applications and a solution manager for Rich Applications at RealDolmen, focus on showing .NET developers how to get their finger on the pulse of data-driven business applications in Silverlight and Windows Phone 7. What’s more, the upcoming Windows 8 will allow developers to build native, immersive Metro-style applications using XAML & C# - exactly what this book is based upon. In other words, the techniques described in this book also apply to Windows 8.

This book is not a general Silverlight 4/5 overview book; it is uniquely aimed at developers who want to build data-driven applications, based on best practices. It focuses on showing .NET developers how to interact with, and handle multiple sources of data in Silverlight business applications, and how to solve particular data problems following a practical hands-on approach, using real-world recipes. It is a practical cookbook that teaches you how to build data-rich business applications with Silverlight that draw on multiple sources of data. Most of the features covered work both in Silverlight 4 and 5. However, we cover some that are specific to Silverlight 5, which will therefore not work with Silverlight 4. Where this is the case, it is clearly indicated.

Packed with reusable, real-world recipes, the book begins by introducing you to general principles when programming Silverlight. It then dives deep into the world of data and services, covering all the options available to access data and communicate with services to get the most out of data in your Silverlight business applications, whilst at the same time providing a rich user experience. This book also covers topics related to storing data locally as well as explaining how to work with data and services in a Model-View-View-Model (MVVM) architecture. Most of the content is applicable to Windows Phone 7 developers as well; a specific chapter on WP7 development is included in this release. By following the practical recipes in this book, which are of varying difficulty levels, you will learn the concepts needed to create data-rich business applications—from the creation of a Silverlight application, to displaying data in the Silverlight application and applying best practices such as MVVM. Each recipe covers a data services topic, going from the description of the problem, through a conceptual solution to a solution containing sample code.

The complete table of contents can be viewed on the publisher’s site: http://www.packtpub.com/microsoft-silverlight-5-data-and-services-cookbook/book

Interested in getting your hands on a copy? You can buy directly from the publisher or go via Amazon or Barnes and Noble, Safari or one of the many online retailers!

Today I think I broke a record: the most popular SilverlightShow webinar, judging from the number of registrations and attendees. Thanks all for joining!

Here are the slides and demos for part 1:

Slides - Demos

Hope to see you for part 2 on February 9th!

On December 6th, I did a webinar on the new features in Silverlight 5. You can download all the material from the below links.

Let’s explore Silverlight 5: Slides - Demos

With a bit of delay, here are the slides and demos of my 2 talks I gave at the SDN Conference in Zeist, The Netherlands.

Let’s explore Silverlight 5: Slides – Demos

Silverlight and Azure: Slides – Demos

Small note: the Silverlight 5 demos were built for the RC version of Silverlight 5 and need a rebuild before they’ll work with the RTM version.

To complete the travelling of 2011, I spent the last week of November touring the entire UK for another user group tour for Telerik (the second one in the UK this year). Telerik is very active in the support of user groups: through the Telerik Insider program, speakers can be requested to go and talk to user groups all over the world, entirely sponsored by Telerik. During the talks, which are deep-dive technical talks, licenses and swag is given to attendees.

This tour brought me in the Northern part of the country, more specifically, I visited a user group in Liverpool, Newcastle, Edinburgh and Aberdeen. At each location, we did 2 sessions. One of these that we “repeated” at each location was an introduction to Windows 8 and WinRT development. This of course triggered a lot of interesting discussion and questions. Each stop also filled their rooms quite well! We were lucky to have good weather (we had, apart from one single rain shower, not a single day of rain in Scotland in the last week of November!) so I made all the cities in place. Also, the weather triggered high show-rates.

I brought home a few things from Scotland, including a cold that is now in its 10th day. This caused me to be delayed in posting all the content. But now, without further delay, here’s all the files (slides and demos) of all talks:

Windows 8 – Windows Runtime: slides – demos

Liverpool: Building a Windows Phone 7 app from start to finish:
slides – demos

Newcastle: Silverlight and Azure
slides – demos

Edinburgh: Building a Windows Phone 7 app from start to finish
slides – demos

Aberdeen: Silverlight 5 for LOB Development
slides – demos

I hope you enjoyed it. Thanks for all the user groups for their work!

About Microsoft TechDays

Year after year thousands of technology professionals come together to network with peers and experts, while diving deep into Microsoft technologies and learning about the latest products and solutions. Microsoft TechDays is one of the premier technical events in Belgium & Luxembourg and not to be missed.

With more technology areas than ever to explore, TechDays 2012 is the perfect place to get up-to-speed on the latest Microsoft technologies and up-level your skill on the technology you use every day. Content will be delivered by industry experts and Microsoft product team members.

Register now

Join our 10^th anniversary edition in a new location (Kinepolis Imagibraine - Braine l'Alleud) and learn about:

• Tooling and languages with Visual Studio, C# and VB
• Cloud development with Windows Azure Platform
• Web development with HTML5, JavaScript and ASP.NET ...
• Windows & Internet Explorer
• Windows Server & Hyper-V
• Windows Phone 7 development
• System Center 2012 & Windows Intune

Kinepolis Imagibraine

After 3 great years in Metropolis Antwerp we’re moving TechDays to a new location: Kinepolis Imagibraine in Braine l’Alleud (Eigenbrakel). The movie theatre is easily reachable both by car and via public transportation.

If you’re coming by train: the Braine l’Alleud train station is very well connected with major cities in Belgium:

- Antwerp: direct connection from Antwerpen-Centraal taking approx. 1 hour
- Ghent: 1 hour trip from Gent Sint-Pieters, switching trains once at Brussel-Zuid
- Brugge: 1,5 hour trip switching trains once at Brussel-Zuid
- Hasselt: 1,5 hour trip switching trains once at Brussel-Zuid
- Leuven: 50 min trip switching trains once at Brussel-Noord
- Mons: 1 hour trip switching trains once at Brussel-Zuid
- Namur: 1 hour trip switching trains once at Charleroi-Sud
- Liège: 1,5 hour trip switching trains once at Brussel-Zuid
- Brussels: 15 minutes from Brussel-Zuid

There is a direct bus line (bus 67 from the TEC company) running from the Braine l’Alleud train station to Kinepolis Imagibraine, taking about 10 minutes.

Coming by car? Kinepolis Imagibraine is just 5 minutes from the R0 highway (exit 24). Driving directions are available here.

I seem to have forgotten to upload the slides and demos of my talk at the UX Tour event last week in Antwerp, Belgium. You can now download them below here.

I’m getting ready for yet another user group tour for Telerik, the second time in the UK and Scotland this year (earlier I did Cambridge, Oxford and several other cities). Since Telerik is sponsoring these sessions, I can give away some licenses on each stop as well! Each evening, we’ll do some deep technical talks on XAML-related topics.

This time, I’m heading more to the North of the country: I’ll be stopping in Liverpool, Newcastle, Edinburgh and Aberdeen. In each city, I’ll be doing 2 talks. For most evenings, some seats are still available so you can still register. All sessions are of course free and some food (I guess pizza :) ) will be available as well.

Registering can be done through the following links.

• Monday 21st November: Liverpool
  Registration: http://thestack-november2011.eventbrite.com
  Sessions:
• Windows 8 Development and WinRT
• Building a Windows Phone 7 app from start to finish
• Tuesday 22nd November: Newcastle
  Registration: http://nebytesgcleerennov2011.eventbrite.com/
  Sessions:
• WinRT and Metro Applications
• Switching on the Cloud for Silverlight
• Wednesday 23rd November: Edinburgh
  Registration: http://gillcleeren2011.eventbrite.co.uk/?ebtv=F
  Sessions:
• Building a Windows Phone 7 app from start to finish
• Windows 8 Development and WinRT
• Thursday 24th November: Aberdeen
  Registration: http://www.aberdeendevelopers.co.uk/post/2011/10/10/ADNUGUK-%E2%80%93-November-2011-Meeting.aspx
  Sessions:
• Windows Runtime and Metro Apps for Windows 8
• Silverlight 5 for LOB Development

I hope to see you there!

While I was teaching a Windows Phone 7 class in Oslo, Norway, I found the time to stop by at the local NNUG user group. I gave 2 talks and as promised, you can download the slides and demos below:

Silverlight 5 LOB Development
MVVM in Silverlight

I hope you enjoyed them, thanks to all attendees (over 70!) for stopping by on such short notice!

I had the privilege to speak at DevReach in Sofia, Bulgaria this week. DevReach is a great conference, sponsored mainly by Telerik. Now in its sixth edition, the conference always manages to have some of the best speakers around, including Scott Hanselman, Carl Franklin, Richard Campbell and many others.

I gave 2 talks on Silverlight. As promised, you can download the code and slide decks below:

Silverlight 5 LOB Development: Slides – Demos
Advanced Silverlight Development: Slides - Demos

On Wednesday 24th August, I gave a webinar on Advanced Silverlight 5 development for SilverlightShow.net. The webinar was attended by a lot of people and I got a lot of great feedback on it. Thanks!

As promised, you can download the slides and the demos from my blog:

Slides

Demos

Today, Wednesday August 24th, I’ll be doing a one hour tour of the advanced new features available in Silverlight 5. I will explain what you’ll be using in 2012 for all your Silverlight needs!

These are some of the topics that will be covered during the session:

• Data binding improvements such as Ancestor RelativeSource, style setter bindings, implicit data templates and debugging options
• Writing custom markup extensions
• Changes in the trusted apps area
• Working with the composition thread
• ICustomTypeProvider
• Miscellaneous improvements such as combobox type-ahead, font changes
• Some topics which are post-beta

The webinar is free of course and you can win a prize!

Registration can be done here.

When developing LightSwitch applications with Visual Studio, a newly created (and built) solution is quite heavy on disk space. We are talking of about 100 – 130MB per solution.

While creating the course material for Ordina’s upcoming LightSwitch course, I typically create many demo solutions, totaling several gigs of DLLs. Luckily, I found a *.cmd file in the downloads of Wrox’s excellent LightSwitch book: Beginning Microsoft Visual Studio LightSwitch Development by István Novák.

Running this file cleans all unnecessary files (which are recreated by Visual Studio) from the solution folder, making it easier to store many solutions on your local disk.

This is the contents of the *.CMD file:

@echo off

del /Q /S /A:H <solutionName>.suo
cd .\<solutionName>

del /Q /S Client\bin
rd /Q /S Client\bin
del /Q /S Client\obj
rd /Q /S Client\obj

del /Q /S ClientGenerated\bin
rd /Q /S ClientGenerated\bin
del /Q /S ClientGenerated\obj
rd /Q /S ClientGenerated\obj

del /Q /S Common\bin
rd /Q /S Common\bin
del /Q /S Common\obj
rd /Q /S Common\obj

del /Q /S Server\bin
rd /Q /S Server\bin
del /Q /S Server\obj
rd /Q /S Server\obj

del /Q /S bin\Debug
rd /Q /S bin\Debug
del /Q /S bin\Release
rd /Q /S bin\Release

del /Q /S ServerGenerated\bin
rd /Q /S ServerGenerated\bin
del /Q /S ServerGenerated\obj
rd /Q /S ServerGenerated\obj
del /Q /S _Pvt_Extensions
rd /Q /S _Pvt_Extensions
cd ..
echo Cleanup completed.
pause

You can download the file from this link as well as a ZIP file: Cleanup.zip (.36 KB). If you download the samples of the book, you’ll have the file as well.

Cleaning your solution comes down to pasting this file in the same directory as where the solution (*.sln) (and *.suo if present)  file are located:

I’m proud to announce that the “Real World .NET 4 and C#” book on which 15 MVPs are working together, is coming close to its release. I’ve written a chapter in this book as well, on Silverlight 5 and MVVM development.

Written by a group of experienced MVPs, this unparalleled book delves into the intricate—and often daunting—world of .NET 4. Each author draws from a particular area of expertise to provide invaluable information on using the various .NET 4, C# 4, Silverlight 4, and Visual Studio tools in the real world. The authors break down the vast .NET 4 Framework into easily digestible portions to offer you a strong foundation on what makes .NET such a popular and successful framework for building a wide range of solutions.

• Breaks down the .NET 4 Framework into easily understandable sections
• Features more than a dozen MVPs serving as authors, each of whom focuses on a particular area of expertise
• Covers such topics as Windows Presentation Foundation, Silverlight 4, Windows Communication Foundation, ASP.NET performance, the entity framework, and more
• Shares C# tips and tricks and .NET architecture best practices from a team of Microsoft MVPs

Real World .NET 4 and C# is the ultimate resource for discovering and understanding the .NET 4 Framework.

The book can be pre-ordered already from Amazon: http://www.amazon.co.uk/Real-World-NET-Silverlight-Indispensible/dp/1118021967/ref=sr_1_1?ie=UTF8&qid=1312574616&sr=8-1

Meanwhile, I’m focusing on my next full Silverlight 5 book, which is due for release end of this year or very early next year!

I’m happy to announce that a new ebook of mine has been published: Getting Ready for Microsoft Silverlight Exam 70-506.

This ebook is based on SilverlightShow 7-part article series ‘Getting ready for Microsoft Silverlight Exam 70-506’. While the online article series give references to many external resources, several for one topic, in this ebook we picked the best resource covering the topic, and have included it as full text, together with links to source code where available. Note: approximately 85% of the resources selected are available in full, the rest of the resources are still included as links due to lack of copy permissions or inability to reach the the respective authors.

This ebook collects a total of 100+ articles in full.

Download Table of Contents (.doc / .docx)

From the author: Silverlight is a rapidly evolving technology. Over a time span of 3 years, it has evolved from being a JavaScript-based platform to a full .NET implementation. With 4 versions released and version 5 in the pipeline at the time of writing, Silverlight has more versions than .NET! That makes it hard for book writers such as me to keep up with new features being added.

It seems to me that it’s also difficult to create and manage exams about Silverlight. For the previous versions of Silverlight, there weren’t any exams available. Silverlight 4 is the first version of which an exam is being created. It was possible to take the beta-exam late 2010; the exam will be officially open in Q1 2011. More information about the exam can be found here: http://www.microsoft.com/learning/en/us/Exam.aspx?ID=70-506&Locale=en-us

With this guide, I aim to make the preparation for the exam a bit easier.

Goal and approach to getting ready

At this point, there’s no official courseware available to study for the exam. In any case, you should therefore be familiar already with Silverlight development. Reading some books on Silverlight will help as well. The list below contains some links to books available for Silverlight 4:

• Silverlight 4 Unleashed
• Silverlight 4 In Action
• Microsoft Silverlight 4 Data and Services Cookbook
• Pro Business Application with Silverlight 4

On top of that, reading articles and blog posts will help you in passing the exam. In this ebook, I try to create an extensive list of resources along with some explanation on the topic at hand that contain the information you need to know. To structure this, we’ll follow the list of topics described by Microsoft on the exam outline page (http://www.microsoft.com/learning/en/us/Exam.aspx?ID=70-506&Locale=en-us#tab2):

• Laying Out a User Interface (15%)
• Enhancing the User Interface (14%)
• Implementing Application Logic (16%)
• Working with Data (17%)
• Interacting with a Host Platform (11%)
• Structuring Applications (13%)
• Deploying Applications (13%)

(Small note: the outlined percentages total 99%, so you’ll probably get 1% for entering your name!)

Last week, I travelled through the UK to give a total of 8 sessions for Telerik to 4 chapters of the NxtGenUg.net user groups. More specifically, I went to Hereford, Oxford, Coventry and Cambridge. It was a pleasure being there, since we had some nice discussions throughout the talks (which of course caused all sessions to run longer than expected, some about 2,5-3  hours :) ). For the first time, I did everything by train and all went well (not a single delay on the 10 trains I took in the UK. I even had to pass through London when going from one station to another to go from Coventry to Cambridge).

This tour was sponsored again by my good friends at Telerik, which help to get speakers to user groups with the program I am in. If you have a user group yourself and want me to come over, let me know! It’s entirely free and I can give away some nice swag and licenses at each talk!

Here are some pictures of last week:

And as promised, here are all the slides and demos of all the sessions:

• Hereford:
  • Databinding in Silverlight
  • MVVM in Silverlight and WPF
• Oxford:
  • Building a LOB application in Silverlight 4
• Coventry:
  • jQuery in ASP.NET and ASP.NET MVC
  • RIA Services in Silverlight 4
• Cambridge:
  • MVVM in Silverlight and WPF
  • RIA Services in Silverlight 4
    

Last week, I did another webinar for Silverlight Show titled Expression Blend 4 for developers. If you were unable to attend, you can view the recorded version on-demand here (it’s free :) )

The slides can be found here and the demos you can download here.

Enjoy!

Community Day 2011 is over (sadly)… But since we had so much fun, that isn’t a problem: we have a great day of Belgian community at its very best! Judging from the feedback, this was the very best edition so far, so that’s good news :)

We had over 300 attendees seeing 32 sessions spread over 5 tracks. Most slides are already available from the agenda page.

I want to thank you all for being there. Of course, a big thank you to the team, the sponsors and the people from BBDO!

Here are some pictures of the event, the entire list can be seen here.

Tomorrow, Thursday June 16th, I’ll be doing another webinar for SilverlightShow. I think that this one if the 7th webinar I’m doing for them!

This one is totally devoted to Expression Blend: Expression Blend for developers. That means (sadly) that I won’t be doing any drawing or graphics-related stuff! I’m going to talk about how I think XAML developers can be more productive with Expression Blend instead of only using Visual Studio for their work.

This is the agenda:

• 5-minute guided tour of Blend
• Great work starts with a sketch: SketchFlow
• Push the button: sample data generation
• Binding with Blend: how to use data-binding
• Customization bonanza
  • Styling
  • Resources and resource dictionaries
  • Templates
  • A custom control
• Blend behaving badly: behaviors
• Animations and other moving things
• Blend welcomes WP7
• The Blend-bag-of-tricks

The outline of the webinar is here and of course you can subscribe for free. The webinar takes about 75 minutes.

A nice extra is that my publisher (Packt Publishing) is giving away 3 copies of the LITE edition of the book I wrote together with Kevin Dockx. So by simply attending, you could win a book!

I hope to see you online tomorrow!

I enjoyed a lot being at NDC 2011 (Oslo, Norway) again for the second year. I gave two sessions, one on LightSwitch and a second one on Expression Blend. I hope you enjoyed them. If you have any questions, please don’t hesitate to contact me!

Here are the downloads as promised

Switch on the LightSwitch: Slides – Demos

Expression Blend 4 for developers: Slides - Demos

The passed TechDays Belgium were another great event, showing that Belgians really know how to organize an event. If you couldn’t attend, you missed a lot to be honest.

But, fear not my dear reader, as all sessions have been recorded and you can see them for free on Channel9: http://channel9.msdn.com/Events/TechDays/TechDays-2011-Belgium 

My personal favorites:

• Scott Hanselman’s keynote
• Jeff Prosise on Silverlight 5
• And my absolute favorite… LightSwitch :)

I haven’t had the time to blog about it, but yes, you can register for Community Day 2011 since a few days. Registrations are going fast, so the best advice I can give you is to register quickly!

The event is still entirely free (including food) and we are again in Utopolis Mechelen. The venue is completely renovated, giving us a lot more space.

This year, we are celebrating our 5th edition. For this occasion, we are inviting 2 Dutch user groups (DotNed and Sixin) who will give sessions at the event as well. We are also doing 30 sessions instead of 24, so you’ll have more choice than ever to fill your free day of learning.

Convinced? I bet you are! Go here for registration, check out our sponsors or take a look at the agenda!

I will see you on June 23rd!

Suppose you’re willing to start learning Silverlight enterprise development and you want a good book to start. There are quite a few really good books on the market covering Silverlight 4. If you’re interested mostly in getting to know how to work with data, services and other enterprise-related topics, my own book is a really good start (here you can read some reviews as well).

If you’re not really sure on whether my book will help you, you can purchase a lite (light) version of it now for a mere $9.95. That’s right: you get a few relevant chapters without spending a lot of cash. You can read more about it here.

Here’s what you get:

• Design and develop rich data-driven business applications in Silverlight
• Rapidly interact with and handle multiple sources of data and services within Silverlight business applications
• Understand sophisticated techniques to work with data in your Silverlight business applications, including displaying data in Silverlight applications, binding data to Silverlight controls, getting data from services into Silverlight applications and much more!
• Packed with practical, hands-on cookbook recipes, illustrating the techniques to solve particular data problems effectively within your Silverlight business applications
• eBook available as PDF download

I just noticed that all DevDays 11 Netherlands sessions are available for online viewing. You can see them here. My talk on jQuery can be found here. Looking at the comments, I think attendees (around 350 I guess) liked what they saw :)

All slides and demos are available here in case you want to try out what I’ve been showing in the talk!

On May 26th, Ordina is organizing a free technology event. Ordina’s technology specialists will give 21 sessions of 30 minutes, spread over 5 tracks. The event is free for everyone to join, registration is required. You can register here: www.ordina.be/differentiate.

We will have the following sessions for you to attend:

Agenda: Stand out from the crowd with Microsoft technology on May 26, 6 pm
30-minute sessions – the choice is yours
.Net
    Visual Studio LightSwitch
    Building a Windows Phone7 application: lessons learnt
    C#5 Async
SharePoint
    Automated scripted deployment of SharePoint
    SharePoint 2010: architectural overview
    Developing against SharePoint 2010 lists
SQL
    Where .Net meets SQL Server: SQL CLR
    Extending to multilingual reporting
    Using geo data within Report Builder 3.0
Application Lifecycle Management     
    Automate your deployment cycle with TFS Build 2010 and Workflow 4
    Delivering quality software with TFS 2010
    Team Explorer Everywhere: TFS and Java, better together
Azure
    Reporting services in the cloud
    Moving a legal application in the cloud
    Windows Phone7 and the cloud
Infrastructure
    Unified Communications: Lync
    Unified Communications: Office 365
    Hyper-V
Enterprise Portfolio Management
    Demand management using workflow in Project Server 2010
    Bridging the project and work management gap

Interested? Join us!

To round things up, here are the slides and demos of my WebMatrix talk at GeekNight (DevDays) in The Netherlands.

Slides
Demos

And here are the slides and demos of my jQuery talk at DevDays Netherlands 2011.

Slides
Demos

I hope you enjoyed the talk!

As promised, here are the slides and demos of my LightSwitch presentation at TechDays 11 Belgium. Thanks for attending (it was a full room of about 500 people!!)

Slides
Demos

With the great weather we’re having, it’s even more obvious that summer is approaching. And we all know what that means, don’t we?

Indeed, Community Day 2011 is coming closer! This fifth edition will be the biggest one we ever did, with more sessions, the best food, great networking opportunities and the best speakers the Belgian (and who knows…) has to offer.

We’ve had a tremendous response from sponsors already and we’re proud to announce the following companies as our sponsors for this year’s edition:

Of course, Community Day 2011 is again a joint event of 13 Belgian user groups. The following user groups are part of this year’s edition:

We’re currently working hard on the agenda, which will be online in 2-3 weeks. At that point, you’ll be able to register as well. Just like previous editions, Community Day 2011 is still a free event.

At this point, I suggest you add the event to your calendar by opening this *.ics file.

To help spread the word about the event, use the following blog bling! Thanks for helping!

As part of the Telerik Insider program, I’ll be touring in the UK this summer. More specifically, I’ll be speaking in Oxford, Hereford, Cambridge and Coventry. On each event, attendees can win a full Telerik license!

You can register here for the events:

• Hereford (July 4th 2011)
  http://www.nxtgenug.net/ViewEvent.aspx?EventID=404
• Oxford (July 5th 2011)
  http://www.nxtgenug.net/ViewEvent.aspx?EventID=405
• Coventry (July 6th 2011)
  http://www.nxtgenug.net/ViewEvent.aspx?EventID=406
• Cambridge (July 7th 2011)
  http://www.nxtgenug.net/ViewEvent.aspx?EventID=407

I hope to see a lot of you in the UK! (and while you’re at it, reserve me some nice weather!)

About 2 weeks ago, the Telerik insider program has been made official (I only found time to blog about it since we bought a house in that week, causing a lot of extra stress and work :) ). I’m very happy that the word on the program is now official AND that I was one of the first to be part of this fantastic initiative.

Let me start by explaining what the program is all about: The Insiders Program, a speaker’s bureau for the community run by Telerik, is comprised of 14 (thus far) passionate and influential speakers conducting a variety of sessions at community events and user groups. Check out their profiles and abstracts here and our FAQ page for detailed information. The full explanation can be found here: http://blogs.telerik.com/blogs/posts/11-04-04/telerik_insiders_are_out.aspx .

The official press release can be found here: Telerik Emphasizes Commitment to Developer Community with Globally Expanded Insiders Program. Some interesting quotes:

The Telerik Insiders Program delivers added value by providing entrée to influential speakers willing to share their .NET knowledge, insight, and expertise,” said Svetozar Georgiev, CEO of Telerik. 

“I cannot express enough how much of a benefactor Telerik has been to our community throughout the last several years. They support user groups and community events by providing much-needed resources and help, but also go that extra step by providing top-notch, quality speakers who are passionate about training and knowledge-sharing,” says Pensacola User Group leader, Karla Landrum.

“User groups and regional events are really the heart of the developer community – they provide unique opportunities for peer-to-peer engagement, and facilitate sharing of real-world development best practices,” said Emily Parker, Community Program Manager at Telerik.

I was “enrolled” in the program December 2009 and have done quite a few speaker engagements since then. I went to VBUG UK, visited user groups all over Sweden and the Netherlands… This year, I’ll be visiting the UK (5 user groups) and Ireland (5 user groups) in the coming months.

What’s in it for you

The good news is that you can benefit from this program as well. If you have a user group (just about anywhere), you can contact us (insidersprogram@telerik.com) to have a Telerik Insider at your next event. All for free. Just send a mail and we can discuss things.

This Wednesday, April 20th, I’ll be doing a webinar on LightSwitch on SilverlightShow!

LightSwitch is a new part of the Visual Studio family and makes it possible to more easily create professional-quality business applications for the desktop, the web, and the cloud. The big question of course: Is LightSwitch something for you?

In this webinar, you’ll get the answer! Silverlight MVP Gill Cleeren will show how you can build professional LOB applications quickly using LightSwitch. We will cover why you should look at LightSwitch, binding to data, and building out the user interface. LightSwitch is however more than just some predefined screens: developers will love it for its extensibility, which we’ll cover deeply.

As always, the webinar is free but registration is required. You can register here: http://www.silverlightshow.net/news/Upcoming-SilverlightShow-Webinar-Building-LOB-Applications-with-LightSwitch.aspx

At TechDays Sweden, I was able to give away a Telerik license during my talk. The lucky winner gets a full Telerik Ultimate license, worth $1.995! All thanks to the people at Telerik.

And the winner is… Peter Forss! Congratulations!!

And as promised, here are the slides and demos for the Windows Phone 7 presentation.

Slides: http://cid-bd64f22e01fad982.office.live.com/view.aspx/Public/Building%20a%20Windows%20Phone%207%20app%20from%20start%20with%20template.pptx
Demos: http://cid-bd64f22e01fad982.office.live.com/self.aspx/Public/WP7%20End%20to%20end.zip

I just finished my first talk at TechDays Sweden 2011 on jQuery. As promised, you can find the slides and demos here.

I hope you enjoyed the session (sadly not everyone could get in the room) although it was extremely hot in the room. If you have any comments/questions, please send them to me.

Slides: http://cid-bd64f22e01fad982.office.live.com/view.aspx/Public/jQuery.pptx
Demos: http://cid-bd64f22e01fad982.office.live.com/self.aspx/Public/jQueryDemos.zip 

Enjoy!

News update for all UK .NET/Silverlight/Windows Phone 7 developers: I'll be touring the UK in the summer, giving quite a few sessions. This new tour is again sponsored by Telerik, meaning that attendees can win licenses of Telerik!

The following cities are currently on my schedule:

Hereford - 4th July
http://www.nxtgenug.net/ViewEvent.aspx?EventID=404
 
Oxford - 5th July
http://www.nxtgenug.net/ViewEvent.aspx?EventID=405
 
Coventry - 6th July
http://www.nxtgenug.net/ViewEvent.aspx?EventID=406
 
Cambridge - 7th July
http://www.nxtgenug.net/ViewEvent.aspx?EventID=407
 
The exact content will be announced soon. Hope to meet many of you at one of these events!

Have you been willing to start WP7 development but haven't had the time? Well, maybe this will make you creating some spare time!

Microsoft just took the wraps of a new challenge for WP7 development called WP7 Challenge. More can be found on it via http://wp7challenge.com/.

Basically, it's a contest in which you build an app and if it's selected as the winner, you as the developer can go to WPC 2011 for free. Not a bad deal just to build a Windows Phone application :) All apps should be entered before June 6th 2011.

May the best app win!

In the coming months, I’ll be travelling through Europe and doing sessions in quite a few locations. Here’s when and where you can catch me.

It’s going to be a very busy couple of months. I hope to see many of you on one of these events!

Just a small reminder that this Wednesday, I’m doing another SilverlightShow webinar titled “Switching on the cloud for Silverlight”.

What happens if you combine 2 of the hottest technologies for your applications? Find out in this very session!

If we combine the capabilities of Windows Azure with the rich UX of Silverlight, we are capable of building great... what am I saying: exceptional web applications. We'll look at building an app in Silverlight running from Azure and we'll look at the topics of interest that you'll encounter when hosting services in the cloud to be consumed from Silverlight, considerations for Windows Azure Storage if used from Silverlight etc.

Webinar agenda:

1. Parts of Windows Azure

2. Why does a Silverlight developer need to care?

3. Developing for Windows Azure

   • Required tools

   • Emulators (“local cloud”)

   • Azure Portal

4. Moving Silverlight applications to the cloud

   • Database only

   • WCF

   • REST

   • Entire Silverlight applications

   • RIA Services

   • Azure as intermediate layer for Twitter

5. Using blob storage

   • Silverlight/Azure video player

6. Windows Phone and Azure

   • Accessing services in the cloud

   • WP7 Push Notification services

As always, these webinars are free and you can register here: http://www.silverlightshow.net/news/Upcoming-Silverlight-Show-Webinar-Switching-on-the-Cloud-for-Silverlight.aspx

If you are one of my Norwegian readers (or any other reader willing to visit the great city of Oslo while learning WP7 :) ), I’ll be teaching Silverlight and Windows Phone 7 at ProgramUtvikling in Oslo, Norway in the coming months.

You can register now for the Windows Phone 7 training already using this link.

Writing Apps for a phone was never so easy. With Silverlight you can build applications for the Windows Phone 7 as easy as you can build a web widget. When youre ready to dive into building applications for phones, this is the course for you.

Silverlight for Windows Phone 7 is a three–day course on Windows Phone 7 Series development using Silverlight. It divides the content into three distinct areas: Design, Development and the Server–Side. Students should be able to develop applications for the phone once they have attended the course. The Course is structured with a mix of didactic lessons, demonstrations and hands–on labs. Each student will leave the course having created several small Silverlight applications. This variety of learning techniques will ensure that all students become proficient in the technology quickly and in an exciting way.

The reason I haven’t been blogging here is that I was busy writing the Silverlight exam guide. The good news is that the entire guide is now ready and available at SilverlightShow! Here are all the parts for you to explore

• Getting ready for Microsoft Silverlight Exam 70-506 (Part 1)
• Getting ready for Microsoft Silverlight Exam 70-506 (Part 2)
• Getting ready for Microsoft Silverlight Exam 70-506 (Part 3)
• Getting ready for Microsoft Silverlight Exam 70-506 (Part 4)
• Getting ready for Microsoft Silverlight Exam 70-506 (Part 5)
• Getting ready for Microsoft Silverlight Exam 70-506 (Part 6)
• Getting ready for Microsoft Silverlight Exam 70-506 (Part 7)

Enjoy!

I was notified that part 2 of my Silverlight exam preparation guide was made available at SilverlightShow. You can read part 2 here: http://www.silverlightshow.net/items/Getting-ready-for-Microsoft-Silverlight-Exam-70-506-Part-2.aspx .
Enjoy!

Today, I got some great news: some of my sessions that I proposed for Mix 11 in Las Vegas made the first cut! That means that you can now all vote for them via the OpenCall page on the Mix 11 site!

So, want me out of here? This is your chance to send me to Vegas, baby!! Voting can be done here: http://live.visitmix.com/OpenCall . All votes are really appreciated, thanks in advance!

These are my sessions that made the first selection:

• Data access from Windows Phone 7
  Gill Cleeren
  Windows Phone 7 apps need access to data, that's a sure thing. In this session, we'll look at what of our knowledge from Silverlight we can leverage into the Windows Phone platform. We'll look at what we need to keep track of on the service side and what actions we need to do on the phone platform itself.
  Level 300
  Technology: Silverlight, Windows Phone 7, Services
• The session where Hello World is forbidden: Advanced Silverlight
  Gill Cleeren
  Byebye 'Hello World'. We've all had the time to play with Silverlight by now so it's time to switch gears. In this advanced Silverlight session, Gill Cleeren will show you advanced topics in Silverlight, such as unit testing, profiling, MEF, security and authentication, advanced printing scenarios, sockets etc... You'll learn stuff that you were afraid to ask about before!
  Level 400/Silverlight experience required.
  Technologies: Silverlight 4
• Advanced WCF RIA Services
  Gill Cleeren
  Since Silverlight 4, WCF RIA Services has been part of the platform. We all had some time to experiment with RIA Services a bit, didn't we? So now it's time for the serious work. In this session, we won't be creating your basic "Hello RIA Services" application! Instead, we'll take a deeper look at RIA services by answering questions such as:How should we architect our applications around them?What patterns and best practices can be applied? How can RIA Services be used in an MVVM scenario?How can I do validation with RIA services?And much more!
  Level 300
  Technologies: Silverlight 4, WCF RIA Services
• Building custom controls in Silverlight 4
  Gill Cleeren
  While Silverlight has a rich set of controls on board, sometimes you still need a control that does not exist. In Silverlight, there are more options than you ever considered possible to do this. Varying from templating a control to building a control from scratch, we'll cover it all. We'll also look at building a container from scratch!Level 300
  Technologies: Silverlight 4

Love one (or more) of these sessions? Please vote! Thanks!

The Silverlight exam (70-506) is being released soon. Together with the people of SilverlightShow, I decided to create a guide to help with the exam preparation. The first part is online now, you can find it here.

Here’s something interesting from my publisher, Packt Publishing: Microsoft Monday. On Monday 24th of January, Packt is set to release 5 books on Microsoft technologies. To celebrate this, they are giving away a year’s subscription on their entire library of Microsoft books. More info can be found here.

Additionally, all Packt books get a 25% discount if you buy 2 books! That includes my book as well!

My good friends from SilverlightShow have announced their 2011 contest: the Eco Contest! I am selected to be one of the five judges this year!

What is this contest about?
2011 has been declared the International Year of Forests by the United Nations. We at SilverlightShow would like to join the worldwide efforts to promote a broader understanding of sustainable forest management and generate ideas to participate in the celebration of forests throughout 2011 and beyond.

We initiate this year's Forests Eco Contest to show the power that Silverlight technologies have in conveying an idea, and reach a huge audience in no time with striking visual and interactive features. Be a part of this year's challenge; tiny individual steps can lead us to a greener and sustainable future on this planet we all share.

The Contest

We invite you to take part in our contest by creating a Silverlight application that informs about the critical situation with forests preservation, or urges to take actions in protecting this resource. We, on our end, will make sure, that your applications reached as many people as possible.  Please read the Official Rules of our green contest!

The Judges
Cigdem Patlak - community vote winner in SilvelightShow Eco Contest 2010, Silveright MVP
Emil Stoychev - founder of SilverlightShow, Silverlight MVP
Gill Cleeren - Microsoft Regional Director, SilverlightShow Webinar Presenter, Silverlight MVP
Brian Noyes - Microsoft Regional Director, Silverlight MVP
Tim Heuer - Microsoft program manager for Microsoft Silverlight

All the information can be found here: http://contest.silverlightshow.net/

I’ll be at Ordina Netherlands (Nieuwegein) for the ”Innoveer jij mee” event on February 7th.
SilverLight 4 door Gill Cleeren
Op maandag 7 februari a.s. geeft Gill Cleeren een masterclass. Gedurende het programma is er aandacht voor de positionering van Silverlight met name in het licht van desktops en mobile devices (als Windows Phone 7). Natuurlijk is er aansluitend veel aandacht voor de technische in’s and out’s van Silverlight 4 en de wijze waarop applicaties met Silverlight 4 ontwikkeld kunnen worden.

Silverlight is Microsoft’s platform voor het ontwikkelen van Rich Internet Applications (RIA’s) op desktops en mobile devices als Windows Phone 7, Microsoft’s nieuwe mobiele platform.

Microsoft heeft veel geïnvesteerd in Silverlight en Silverlight is inmiddels toe aan zijn vierde iteratie (Silverlight 4) en daarmee klaar voor de ontwikkeling van business applicaties.

Registration is free but obligatory at https://www.ordina.nl/nieuws/evenementen/kennissessie/20110207%20-%20innoveer%20jij%20mee%20-%20silverlight%204%20door%20gill%20cleeren.aspx.

With the new year now almost 2 weeks old, we have put online the first Visug events of 2011 (and we have a great list of upcoming ones as well, more on that soon).

To start with a bang, we have Scott Hanselman doing a session on January 24th! The final session content will be available soon, but it will be in the MVC/NuGet area. As we expect this to be fully booked very soon, register quickly via http://visug.be/Eventdetails/tabid/95/EventId/37/Default.aspx

Secondly, Bart Wullems will be doing a session on Caliburn.Micro.
You've heard a lot about Model-View-ViewModel (MVVM), but you've struggled to see how it can help you in your day-to-day work. Or, you're experienced at implementing MVVM, but looking for some ways to maximize your investment in this methodology. In this session, we explore Caliburn.Micro(http://caliburnmicro.codeplex.com/), a simple MVVM framework, by iteratively identifying pain points in our UI development and eliminating them with simple solutions. You'll walk away with code, but more importantly with an understanding of how to apply some simple ideas to improve productivity with MVVM in your own projects.

Register here: http://visug.be/Eventdetails/tabid/95/EventId/36/Default.aspx

It will be another great Visug year!

On January 24th, the first Belgian Web Camp takes place. Some updates have been done to the agenda, including another speaker being added.

This is the final agenda:

8:30 - 9:00 Welcome and registration

9:00 - 11:00 Opening Keynote – What’s new in the Microsoft Web Platform (Scott Hanselman, Principle Program Manager, Microsoft)
Just recently, Microsoft have released a bunch of new products that web developers can use to build websites and web applications.  Scott, Drew and Jonathan will take you on a whirlwind tour of what’s new in the Microsoft Web Platform, including ASP.NET MVC 3, NuGet and more.

11:00 - 11:30 Coffee Break

11:30 - 12:30 HTML5: How about today? (Katrien De Graeve, Developer Evangelist, Microsoft)
What is HTML5? With more and more browsers supporting HTML5, ECMAScript 5 and other web standards, developers now have a strong web platform they can use to create a new class of web application that is more powerful and interactive than ever before.  What's in HTML5 that lets us take our sites to the next level?
Expect demos and code!

12:30 - 13:30 Lunch

13:30 - 14:45 Come in as jQuery zero, go out as jQuery hero (Gill Cleeren)
jQuery is the web developers’ new favorite. This lightweight JavaScript library has developers writing JavaScript code again, and loving it! What previously needed 20 lines of code can now be done in just 3 lines. Who wouldn’t be enthusiastic? Microsoft showed its love for the library by fully integrating it in Visual Studio. I dare to ask: should you stay behind? In this session, we’ll take a look at jQuery and we’ll teach you what you need to know to get you on your way. More specifically, we’ll look at selectors, attributes, working with WCF, jQuery UI, and much more. You could easily walk out of this session wearing a sticker: “I love jQuery”!

14:45 - 15:15 Coffee Break

15:15 - 16:30 OData: Open Data for the Open Web (Jonathan Carter, Senior Technical Evangelist, Microsoft)
There is no shortage of valuable data being generated by applications, reports, tools, Web sites, etc. Unfortunately, this leaves many of us wishing we could programmatically access the data and logic behind an app, report, or Web site. To break down data silos and increase the shared value of data and its associated business logic through the Web, Microsoft has recently announced the Open Data Protocol which enables exposing any data source as a Web-friendly data feed. Join this session to understand what the Open Data Protocol (OData) is and how it adds end-user and developer value to many of Microsoft's leading products and services (such as SharePoint Server 2010, Microsoft Codename "Dallas", Windows Azure, SQL Server Reporting Services, SQL Server PowerPivot for Excel, Visual Studio, .NET, Silverlight, AJAX, etc.), as well as being accessible from a range of platforms such as Java and PHP. "

16:30 - 17:30 Closing drink

Registration can be completed here (there are a few seats left!!)
Location:
Business Faculty
St. Lendriksborre 6 / Font Saint Landry 6
Brussel - Neder over Heembeek 1120
Belgium

You can also watch the live stream but you need to register from here. And if you want to view the event from within your company, you can get a free breakfast (Register here)

If in this new year, you want to hop onto a new job, why not try Ordina Air? We’re hiring talented people!

Go to ordina-air.ordina.be and check in for your new job!

I just noticed that the book I’m writing a chapter for these days is announced on Amazon already, although the release is still some time away. The book is titled Real World .NET 4 and C#: Indispensible Experiences from 15 .NET and C# MVPs and can be pre-ordered from Amazon from now.

(That’s me on the right there on the cover… ;-) )

They did completely misspell my name though (I got renamed to Gil Gleeren for some reason), I’m looking into getting this fixed.

Meanwhile, my very first book I wrote with Kevin Dockx still keeps doing great and getting great reviews, both at Amazon.com and Amazon.co.uk!

After checking my mailbox frantically for the last couple of hours, I just got my confirmation mail that I’m awarded MVP for the 4th year!

This one was a bit special though, as I’m changed from ASP.NET MVP to Silverlight MVP!

When working with MVVM, the Command pattern is used to bind actions (such as a Click on a Button) in the View with commands in the ViewModel. The ICommand interface in Silverlight has 3 members:

              //
Summary:
            

              //
Defines the contract for commanding, using the same contract as used in WPF.
            

              public
              interface ICommand

{

              //
Summary:
            

              //
Occurs when changes occur that affect whether the command should execute.
            

              event EventHandler
CanExecuteChanged;

              //
Summary:
            

              //
Defines the method that determines whether the command can execute in its
            

              //
current state.
            

              //
            

              //
Parameters:
            

              //
parameter:
            

              //
Data used by the command. If the command does not require data to be passed,
            

              //
this object can be set to null.
            

              //
            

              //
Returns:
            

              //
true if this command can be executed; otherwise, false.
            

              bool CanExecute(object parameter);

              //
            

              //
Summary:
            

              //
Defines the method to be called when the command is invoked.
            

              //
            

              //
Parameters:
            

              //
parameter:
            

              //
Data used by the command. If the command does not require data to be passed,
            

              //
this object can be set to null.
            

              void Execute(object parameter);

}

The fact whether or not the command can be executed (read: a Button is enabled or not) depends on the boolean value returned by the CanExecute. By default, this value is evaluated on first load of the View: a Save button should initially be disabled. However, during user input, this value has to be re-evaluated: after the user has filled in a field, we need to check if the Save button should be enabled. For this purpose, the CanExecuteChanged event exist. This event should be raised whenever the value of CanExecute should be evaluated once again.

In MVVM Light, the lightwork MVVM framework by Laurent Bugnion, a method called RaiseCanExecuteChanged exists on the RelayCommand class for this very purpose. Let’s take a look at how we can use this method.

I have a very basic view, containing some TextBox fields. Note that initially, the Save button is disabled:

The XAML code is shown below. The fields are bound to a Person object, that I expose in the ViewModel (shown further).

              <
              Grid
              Width
              ="450"
              >
            

              <
              Grid.RowDefinitions
              >
            

              <
              RowDefinition
              Height
              ="50"
              ></
              RowDefinition
              >
            

              <
              RowDefinition
              Height
              ="40"
              ></
              RowDefinition
              >
            

              <
              RowDefinition
              Height
              ="40"
              ></
              RowDefinition
              >
            

              <
              RowDefinition
              Height
              ="40"
              ></
              RowDefinition
              >
            

              <
              RowDefinition
              Height
              ="40"
              ></
              RowDefinition
              >
            

              </
              Grid.RowDefinitions
              >
            

              <
              Grid.ColumnDefinitions
              >
            

              <
              ColumnDefinition
              Width
              ="*"
              ></
              ColumnDefinition
              >
            

              <
              ColumnDefinition
              Width
              ="*"
              ></
              ColumnDefinition
              >
            

              </
              Grid.ColumnDefinitions
              >
            

              <
              TextBlock
              x:Name
              ="FirstNameTextBlock"
              Grid.Row="1"

              Grid.Column="0"Text="First
name"VerticalAlignment="Center"Margin="3"></TextBlock>

              <
              TextBlock
              x:Name
              ="LastNameTextBlock"
              Grid.Row="2"

              Grid.Column="0"Text="Last
name"VerticalAlignment="Center"Margin="3"></TextBlock>

              <
              TextBlock
              x:Name
              ="EmailTextBlock"
              Grid.Row="3"

              Grid.Column="0"Text="Email"VerticalAlignment="Center"Margin="3"></TextBlock>

              <
              TextBox
              x:Name
              ="FirstNameTextBox"
              Grid.Row="1"

              Grid.Column="1"VerticalAlignment="Center"HorizontalAlignment="Left"Width="200"

              Margin
              ="3"
              Text
              ="{Binding
Person.FirstName, Mode=TwoWay}"
              ></
              TextBox
              >
            

              <
              TextBox
              x:Name
              ="LastNameTextBox"
              Grid.Row="2"Grid.Column="1"

              VerticalAlignment
              ="Center"
              HorizontalAlignment
              ="Left"
              Width
              ="200"
            

              Margin
              ="3"
              Text
              ="{Binding
Person.LastName, Mode=TwoWay}"
              ></
              TextBox
              >
            

              <
              TextBox
              x:Name
              ="EmailTextBox"
              Grid.Row="3"Grid.Column="1"

              VerticalAlignment
              ="Center"
              HorizontalAlignment
              ="Left"
              Width
              ="200"
            

              Margin
              ="3"
              Text
              ="{Binding
Person.Email, Mode=TwoWay}"
              ></
              TextBox
              >
            

              <
              Button
              Content
              ="Save"
              Grid.Row="4"Grid.Column="1"

              Command
              ="{Binding
SaveCommand}"
              VerticalAlignment
              ="Center"
            

              HorizontalAlignment
              ="Right"
              ></
              Button
              >
            

              </
              Grid
              >
            

The ViewModel called MainPageViewModel is set as the DataContext for this View. This ViewModel exposes a Person instance (a Model class) and a RelayCommand for the View to bind to.

              public
              class MainPageViewModel:
ViewModelBase

{

              public Person
Person { get; set; }

              public RelayCommand
SaveCommand { get; set; }

}

The SaveCommand is initialized as follows:

              private
              void InitializeCommands()

{

    SaveCommand = new RelayCommand(OnSave,
OnCanSave);

}

              private
              void OnSave()

{

              //Perform
save to database
            

}

              public
              bool OnCanSave()

{

              return !string.IsNullOrEmpty(Person.FirstName) 

        && !string.IsNullOrEmpty(Person.LastName) 

        && !string.IsNullOrEmpty(Person.Email);

}

Note that the OnCanSave (the implementation of the CanExecuteChanged) will at this point only be called upon binding of the ViewModel. However, I need this to be evaluated every time a value of the bound Person changes: only after all 3 fields have a value, the Save should be enabled.

To implement this, I changed the Person class as follows. It implements the INotifyPropertyChanged interface.

              public
              class Person
: INotifyPropertyChanged

{

              private
              string _firstName;

              private
              string _lastName;

              private
              string _email;

              public
              event PropertyChangedEventHandler
PropertyChanged;

              public
              string FirstName

    {

        get

        {

              return _firstName;

        }

        set

        {

              if (_firstName
!= value)

            {

                _firstName = value;

              if (PropertyChanged
!= null)

                {

                    PropertyChanged(this, new PropertyChangedEventArgs("FirstName"));

                }

            }

        }

    }

              public
              string LastName

    {

        get

        {

              return _lastName;

        }

        set

        {

              if (_lastName
!= value)

            {

                _lastName = value;

              if (PropertyChanged
!= null)

                {

                    PropertyChanged(this, new PropertyChangedEventArgs("LastName"));

                }

            }

        }

    }

              public
              string Email

    {

        get

        {

              return _email;

        }

        set

        {

              if (_email
!= value)

            {

                _email = value;

              if (PropertyChanged
!= null)

                {

                    PropertyChanged(this, new PropertyChangedEventArgs("Email"));

                }

            }

        }

    }

}

In the constructor of the ViewModel, I register for the PropertyChanged event being raised from the Person model.

              public MainPageViewModel()

{

    InitializeCommands();

    Person = new Model.Person();

    Person.PropertyChanged += 

              new System.ComponentModel.PropertyChangedEventHandler(Person_PropertyChanged);

}

In this event handler, I now call the RaiseCanExecuteChanged method, part of the RelayCommand class of MVVM Light.

              void Person_PropertyChanged(object sender,
System.ComponentModel.PropertyChangedEventArgs e)

{

    SaveCommand.RaiseCanExecuteChanged();

}

This causes the CanExecuteChanged to be raised, causing Silverlight to evaluate again if the Command should be enabled or not. In this particular case, I do this as follows (this code was already shown and executed also on the initial binding):

              public
              bool OnCanSave()

{

              return !string.IsNullOrEmpty(Person.FirstName) 

        && !string.IsNullOrEmpty(Person.LastName) 

        && !string.IsNullOrEmpty(Person.Email);

}

Whenever a value is provided for all 3 fields, the Button will be enabled.

I’m a fan of SketchFlow, definitely. I really like the tool, part of Expression Blend, to create prototypes of applications I’m building. It gives me a means of talking with the stake holders about how I see the application and change where needed. Because of the support for iterative feedback of the prototype, it’s easy to come to a prototype that is a reflection of what the application will look like in the end. At Ordina, we made sure that our analysts know SketchFlow and use it instead of Visio or PowerPoint during the analysis and requirements gathering phase.

One of the questions I do get a lot is whether it is a good idea to start the development of the “real” application with the code created by SketchFlow. I tend to say no on this question. Why you may ask? Well, here are the reasons for this:

• The application prototype is not designed with the real application in mind. Things like where can I create a user control (re-using parts) or a custom control are neglected during the prototyping phase. This is logical: during this phase, you should not be worrying about these things at all.
• In some occasions, the prototype is created by an analyst. Chances are that your analyst will not think about the code you need to write…
• SketchFlow uses styles to create the sketchy look of the controls. You need to remove these manually, which can take some time.

While I say no to reusing the prototype for the final application, I do say yes to perhaps using a part of the generated code.

Enjoy these magical days with your family and loved ones and have a great 2011!

It’s the time of the year again when we everyone starts reflecting on the year that has gone by. While 2010 was great, 2011 is certainly another great one coming up. So instead of thinking of what has been, let’s take a look into 2011… from a Microsoft developer perspective that it :)

While 2010 was the launch year of Visual Studio 2010, in 2011 we’ll get several new things on our plate. No Visual Studio 2011, that’s true, although when thinking about the 18-24 month release cycle of Visual Studio, chances are that we’ll see the first alphas or betas late in 2011. Nothing is disclosed on this at the moment though, so that’s a pure guess of mine.

Silverlight will definitely see a new release in 2011. In H1 2011, we’ll have the beta and in the second half of the year, we’ll have a released version. Silverlight 5 brings many new features, you can watch Scott Guthrie’s keynote on the new version right here.

The statement that was put out with showing the early version of Silverlight 5 put all the blown-out-of-proportion-rumors about Silverlight’s death to rest. It clearly shows that any investment in Silverlight is a safe one, future-proof for years to come. I’m looking forward to doing many sessions on this new version in the new year, that’s for sure!

Heavily related to Silverlight is of course the further development of Windows Phone 7. Released late 2010, the new kid on the block has caused quite a lot of stir in the mobile world. Microsoft created a new, refreshing interface for their devices. Some things are missing, definitely, but due to the easy updating model that is in place, Microsoft can create and distribute updates easily, which is entirely different from previous versions of the mobile OS. Heck, comparing WP7 with Windows Mobile… I should not be doing that! Several (unconfirmed as of yet) updates have been rumored, the first one coming already in January, adding copy/paste functionality as a core function of the phone. Later updates are rumored as well, including a v7.5 in the second half of the year and even Windows Phone 8 in 2012. While these are based on rumors, it shows that Microsoft is both committed to the platform AND investing heavily in creating new, updated version of the OS.

For me as a Silverlight developer, Windows Phone 7 was a gift. I practically didn’t have to learn anything new to become a mobile developer. The tooling around Windows Phone development is by far the best there is, just install the tools in Visual Studio and you’re good to go.

I now personally have a Samsung Omnia 7 (coming from an iPhone 3Gs) and I love the phone. It’s fast, stable (I didn’t restart it since I have it I think)… True, applications are still lacking a bit, but consider that the phone is only here for a couple of months and consider also there are already over 4000 apps in the store and you’ll understand that we’ll have an interesting year there as well. Oh and yes, Angry Birds will be coming to Windows Phone 7 as well (as said by Rovio on Twitter).

Speaking of mobile, 2011 certainly will be the year of the tablet. At CES, taking place in January, there will be a flood of tablets coming out. Small, large, somewhere in between, running Android or Windows 7, we’ll see them all. I do hope here on a strong answer from Microsoft, but there’s nothing confirmed yet. I’m sure we’ll see some really interesting stuff there as well.

To finish off with, let’s hope we’ll see in the new year the next version of Windows (Windows 8??) in some form. There’s very little known currently about the new OS though.

Enjoy these last days of 2010!

I noticed the video recording of my webinar “Building an end-to-end Silverlight 4 application” is now online (90 minutes). I hope you enjoy it and if you have questions, please contact me via mail or comments.
Video
Slides and demos were posted here

Since Silverlight 3, we have had the Navigation Application template available. Using this template, we did not need any tricks anymore to do navigation between “pages” (which did not exist in Silverlight 2, we only had the UserControl). In SL3, a Navigation Application was however rather locked down: developers had little to none options available to hook into the navigation process itself.

With Silverlight 4, the INavigationContentLoader interface was introduced. This interface provides a means for us to override how the navigation framework works: we can provide our own logic for the page-loading process. Based on the target URI that is passed in, we can load the page, but we can do other actions as well first. Let’s first look at this interface:

              public
              interface INavigationContentLoader

{

    IAsyncResult BeginLoad(Uri targetUri, Uri currentUri, 

        AsyncCallback userCallback, object asyncState);

              void CancelLoad(IAsyncResult
asyncResult);

              bool CanLoad(Uri
targetUri, Uri currentUri);

    LoadResult EndLoad(IAsyncResult asyncResult);

}

Because we can provide whatever functionality we want, this simple interface does much more, we can practically do whatever we want when a user clicks on a link. Think of actions such as the following:

• The target URI could contain the name of the XAP file in which the XAML view can be found (ex. MyXap.xap/View1.xaml). Our custom logic could check if this XAP file is already available/downloaded on the client. If not, it can be downloaded on-demand.
• Check that the user has permissions to see the requested URL.
• Load the ViewModel corresponding to the View that is navigated to.
• Pass parameters to the constructor of a page
• …

The flow to load a page (and the corresponding calls can be seen in the interface):

• A check is done using the CanLoad method if the requested page can be found. This can be a location to handle in our own way how errors resulting from navigating to a non-existing page are shown to the user.
• The page loading process is using a cancellable asynchronous way to load pages, starting with the BeginLoad. In the BeginLoad, we, quite logically, start the loading process.
• Once BeginLoad started the loading process, the navigation framework waits for the loading to be complete. Once complete, the Endload is called. In normal circumstances, the LoadResult is a fully initialized Page that can now be displayed to the user.

Let’s now look at a small sample. Assume we have a service that returns, based on the role name of the logged-in user, a list of pages the user has access to.

[OperationContract]

              public List<SitePermission>
GetAccesiblePages(string roleName)

{

              switch (roleName)

    {

              case
              "user":

              return
              new List<SitePermission>() 

            {

              new SitePermission(){PageName="/Views/Home.xaml",Allowed= true},

              new SitePermission(){PageName="/Views/About.xaml",Allowed= true},

              new SitePermission(){PageName="/Views/Products.xaml",Allowed= true},

              new SitePermission(){PageName="/Views/Admin.xaml",Allowed= false}

            };

              case
              "administrator":

              return
              new List<SitePermission>() 

            {

              new SitePermission(){PageName="/Views/Home.xaml",Allowed= true},

              new SitePermission(){PageName="/Views/About.xaml",Allowed= true},

              new SitePermission(){PageName="/Views/Products.xaml",Allowed= true},

              new SitePermission(){PageName="/Views/Admin.xaml",Allowed= true}

            };

              default:

              return
              new List<SitePermission>() 

            {

              new SitePermission(){PageName="/Views/Home.xaml",Allowed= false},

              new SitePermission(){PageName="/Views/About.xaml",Allowed= false},

              new SitePermission(){PageName="/Views/Products.xaml",Allowed= false},

              new SitePermission(){PageName="/Views/Admin.xaml",Allowed= false}

            };

    }

}

In our Silverlight code, we download this list upon start of the application and which each navigation action, we check if the target URI is allowed to be accessed by the user. Because we want to do this using the navigation application template, we need to write a custom implementation of the page loading.

To do this, we start by adding a class that implements the INavigationContentLoader interface.

              public
              class AutorizedPageContentLoader:INavigationContentLoader

{

    ...

}

To keep things simple initially, we’ll use the default instance for the page loading process, we’ll only change the CanLoad implementation. In the CanLoad, we need to access the list of SitePermissions, downloaded from the service. The following code is the service call, which was placed here in the App.xaml.cs (could be placed in a custom bootstrapper as well):

              public ObservableCollection<SitePermission>
SitePermissions { get; set; }

              private
              void Application_Startup(object sender,
StartupEventArgs e)

{

    LoadSitePermissions();

}

              private
              void LoadSitePermissions()

{

    AuthorizedPageService.AuthorizedPageLoadServiceClient client = 

              new AuthorizedPageService.AuthorizedPageLoadServiceClient();

    client.GetAccesiblePagesCompleted += (s, e) =>

    {

        SitePermissions = e.Result;

              this.RootVisual
= new MainPage();

    };

    client.GetAccesiblePagesAsync("user");

}

The CanLoad now checks this list and returns true or false based on the requested Uri.

              public
              bool CanLoad(Uri
targetUri, Uri currentUri)

{

    var item = ((App)Application.Current).SitePermissions.

        Where(s => s.PageName == targetUri.ToString()).FirstOrDefault();

              if (item
!= null)

    {

              return item.Allowed;

    }

              return
              false;

}

The BeginLoad, EndLoad and CancelLoad can be handled using the default instance of the page loading process:

              private PageResourceContentLoader
_loader = new PageResourceContentLoader();

              public IAsyncResult
BeginLoad(Uri targetUri, Uri currentUri, 

    AsyncCallback userCallback, object asyncState)

{

              return _loader.BeginLoad(targetUri,
currentUri, userCallback, asyncState);

}        

              public
              void CancelLoad(IAsyncResult
asyncResult)

{

    _loader.CancelLoad(asyncResult);

}

              public LoadResult
EndLoad(IAsyncResult asyncResult)

{

              return _loader.EndLoad(asyncResult);

}

The final thing we need to do is of course making sure that our content loader implementation is used by the navigation frame.

              <
              navigation:Frame
              x:Name
              ="ContentFrame"
              Style
              ="{StaticResource
ContentFrameStyle}"
            

              Source
              ="/Home"
              Navigated
              ="ContentFrame_Navigated"
            

              NavigationFailed
              ="ContentFrame_NavigationFailed"
              >
            

              <
              navigation:Frame.UriMapper
              >
            

              <
              uriMapper:UriMapper
              >
            

              <
              uriMapper:UriMapping
              Uri
              =""
              MappedUri
              ="/Views/Home.xaml"
              />
            

              <
              uriMapper:UriMapping
              Uri
              ="/{pageName}"
              MappedUri
              ="/Views/{pageName}.xaml"
              />
            

              </
              uriMapper:UriMapper
              >
            

              </
              navigation:Frame.UriMapper
              >
            

              <
              navigation:Frame.ContentLoader
              >
            

              <
              local:AutorizedPageContentLoader
              ></
              local:AutorizedPageContentLoader
              >
            

              </
              navigation:Frame.ContentLoader
              >
            

              </
              navigation:Frame
              >
            

When the user now navigates to the Admin page (which is not allowed), the navigation will not be allowed.

OK, now what is a webcamp then?
Microsoft Web Camps are free events that allow you to learn and build on the Microsoft Web Platform. Good news: Web Camps are coming to Belgium!

The Belgian Web Camp event on 24th of January 2011 is a full-day event where will hear from Microsoft experts on the latest components of the platform, including ASP.NET MVC 3, jQuery, HTML5, OData and WebMatrix.
Scott Hanselman is doing a two-hour keynote together with James Senior. I’ll be doing the oData and JQuery sessions and Katrien De Graeve is doing the HTML5 talk.

Two options to registering for the event:

1. Register to attend in-person: https://msevents.microsoft.com/CUI/EventDetail.aspx?EventID=1032472434&Culture=en-US
2. Register for the keynote live stream and see how you could have free breakfast delivered to your company: https://msevents.microsoft.com/CUI/WebCastEventDetails.aspx?EventID=1032472819&EventCategory=2&culture=en-US&CountryCode=US

Location: Business Faculty
St. Lendriksborre 6 / Font Saint Landry 6
Brussel - Neder over Heembeek 1120
Belgium
Timing: Monday 24 January 2011 – 8:30 to 17:00

Full agenda:

8:30 9:00

Welcome and registration

9:00- 11:00

Opening Keynote by Scott Hanselman and James Senior on ASP.NET MVC 3 and WebMatrix

11:00- 11:30

Coffee Break

11:30- 12:30

HTML5: How about today? (Katrien De Graeve)

What is HTML5? With more and more browsers supporting HTML5, ECMAScript 5 and other web standards, developers now have a strong web platform they can use to create a new class of web application that is more powerful and interactive than ever before. What's in HTML5 that lets us take our sites to the next level?
Expect demos and code!

12:30- 13:30

Lunch

13:30- 14:45

Come in as jQuery zero, go out as jQuery hero (Gill Cleeren)

jQuery is the web developers’ new favorite. This lightweight JavaScript library has developers writing JavaScript code again, and loving it! What previously needed 20 lines of code can now be done in just 3 lines. Who wouldn’t be enthusiastic? Microsoft showed its love for the library by fully integrating it in Visual Studio. I dare to ask: should you stay behind? In this session, we’ll take a look at jQuery and we’ll teach you what you need to know to get you on your way. More specifically, we’ll look at selectors, attributes, working with WCF, jQuery UI, and much more. You could easily walk out of this session wearing a sticker: “I love jQuery”!

14:45- 15:15

Coffee Break

15:15- 16:30

Oh, look at that data: using oData to expose your data over the web (Gill Cleeren)

While applications, sites, tools all generate tons of useful data, it is sometimes hard to access that data from your own application. To increase the shared value of data, Microsoft has introduced the Open Data protocol. Using Open Data, we can expose any data source as a web-friendly data feed.
In this session, we'll start by looking at oData, to make sure that everyone is on board with all the concepts. We'll see how it adds value for the developer and the end user for many of Microsoft's products and services. We'll then look at how we can build our own oData services using WCF Data Services, from working with the basic concepts to more advanced features such as query interceptors and service operations.
Come and learn about information and entity services that are stunning in their simplicity!

16:30- 17:30

Closing drink

Yesterday, I did another webinar for SilverlightShow titled “Building a Silverlight application end-to-end”. During the presentation (which took about 90 minutes), we had over 200 people attending which was great!

The goal of the presentation was giving an overview of topics that developers will encounter when building real world applications with the Silverlight platform:

1. SketchFlow
2. WCF RIA Services
3. Data binding & DataGrid
4. MVVM
5. MEF
6. Commanding & behaviors
7. Messaging, navigation & dialogs
8. Custom controls & third party controls
9. OOB
10. Printing

A video will be available shortly, meanwhile, you can already download the slides and demos here:
Slides - Demos

Yesterday, I got to do my very first presentation ever at TechEd Europe. The title of the session was "What you as an ASP.NET developer need to know about jQuery". The focus of the talk was of course jQuery and where it can be used in combination with the ASP.NET platform, both WebForms and ASP.NET MVC. More specifically, I covered the following topics:

Why jQuery?
jQuery fundamentals
Creating and manipulating elements
Events
Animations and effects
Talking to the server
jQuery UI
Writing plugins
Breaking news around new releases
Using the CDN

The room was full with over 350 attendees and I got some great feedback. Thanks to all people that visited my talk, really appreciated.

As promised, here are the slides and ALL the demos (including the ones I did not talk about in the session):
Slides
Demos

Now that PDC10 is over and after rumors (mostly because people saw “things” in an article that weren’t there at all by the way), Microsoft has officially made clear to the world that it is fully committed to Silverlight, that it keeps investing heavily in the platform, that there will be future versions, that Belgium finally has a government (got you there ;) ) and thus Silverlight is all but dead!

Don’t take it from me of course, but start by reading the statements made by Bob Muglia and Steve Ballmer .

In short, we can easily say (as mentioned in my previous post) and confirm once again that all your investments in Silverlight are safe. If you planned (part of) your career betting on Silverlight, it’s a great bet and one that won’t let you down. In fact, you’ll start seeing more and more return of your investments in the coming time. Take for example Windows Phone 7, which is (almost) here. Over a 1000 (!) apps are already in the store and many more are on their way. Most of them being Silverlight of course!

Back to my statements around HTML5 and Silverlight. Taking a look at the final paragraph in Bob Muglia’s post:
The purpose of Silverlight has never been to replace HTML, but rather to do the things that HTML (and other technologies) can’t, and to do so in a way that’s easy for developers to use.  Silverlight enables great client app and media experiences.
As said, Silverlight is aimed at things HTML is not intended for: business apps. Sites are great with HTML, and can be built with Silverlight. Apps are great with Silverlight but can be built (most of the time…) with HTML. Each has its function and they will co-exist.

I really hope that all this clarifies things for everyone, including developers and customers. Should you have questions, please don’t hesitate to contact me.

Some other interesting articles on this:

• http://johnpapa.net/silverlight/silverlight-tv-50-scott-guthrie-discusses-the-state-of-silverlight/
• http://timheuer.com/blog/archive/2010/11/01/silverlight-is-dead-long-live-silverlight.aspx

(More added later)

I’ve been quite late reading all the buzz that appeared after Mary-Jo Foley wrote an article titled “Microsoft: Our strategy with Silverlight has shifted”. Basically, if you don’t want to read it, it comes down to a few things:

• No Silverlight being shown in the PDC keynote, only HTML5
• She asking Bob Muglia how Microsoft sees Silverlight evolving
• Bob Muglia responding

  “Silverlight is our development platform for Windows Phone,” he said. Silverlight also has some “sweet spots” in media and line-of-business applications, he said.

  But when it comes to touting Silverlight as Microsoft’s vehicle for delivering a cross-platform runtime, “our strategy has shifted,” Muglia told me.

  Silverlight will continue to be a cross-platform solution, working on a variety of operating system/browser platforms, going forward, he said. “But HTML is the only true cross platform solution for everything, including (Apple’s) iOS platform,” Muglia said.
  

Of course, this triggered a lot of reaction and it’s quite funny to follow on Twitter (#silverlight). But more about that in a minute, first some background is in place I guess.

HTML 5 and Silverlight
You won’t hear me denying that HTML5 will be big… some day. While most browsers are starting to implement HTML5 features, the standard is far far (x100) away. It could take years before there’s a standard. Years you say? Yes indeed. Years in this sector is like decades in other industries. That means things will change. Denying that would be foolish. While betting early is a good thing, there’s something like too early as well. That said, HTML5, like HTML4 is still a markup language. Yes it can now create games where dozens of fish swim around (that won’t be my next LOB app probably but anyway). Yes it has the Canvas and a lot of other goodness. Did I say it will be great?

On the other hand, we have Silverlight. Today in version 4, so that’s mature. It is today helping thousands of developers building great (LOB) applications (without swimming fish). It will evolve (why wouldn’t it) and there’s no need to wait years for an updated version (Microsoft has released 4 versions of Silverlight in 3 years!), so if changing needs come around, it’s easy to add them to the platform.

And then came PDC2010
While not many where creating an issue out of the fact that several technologies (Silverlight, Flash, HTML5) were growing steadily next to one another, a few weeks back, things started to shake a bit and then all of a sudden, PDC2010 came along and now everyone thinks Microsoft will abandon Silverlight.

In fact, Microsoft is saying that some stuff they previously thought you should do in Silverlight, you should do in HTML5. That’s not a big deal. I’ve always (like many other Silverlight developers) been of the idea that Silverlight should not (in many cases) be used to build entire internet sites with (I haven’t built my blog in Silverlight, did I?). When using Silverlight (and the same goes for Flash here) in internet scenarios, it’s often better to have “islands of Silverlight”, parts of the page in Silverlight that is. Look at what Shawn says here:

Silverlight is good for Apps; HTML is good for sites.

I totally agree. It depends on what you need to build, but that’s just what makes that we need all the technologies, not one! Are you going to build real business apps using JavaScript? OK, you CAN do it (there are some large ones out there, I’ve been on the internet…). But by the time you are done writing your app with JavaScript, I’ll be enjoying some vacation probably, because I could enjoy the strengths of my managed language that sits behind Silverlight.

Also, Microsoft is pushing Silverlight for devices and WP7. It’s brother, WPF, is alive and kicking (although again a small group thinks it’s dead as well).

Where does that leave us now?
If you invested in Silverlight, don’t worry. Silverlight is here today and it will be here tomorrow as well. Never done any Silverlight yet, well then there’s no better time to start than now. Silverlight is mature and can be the next best thing to build your apps with. Learn HTML5 as well, as that will be big as well. And perhaps, you can combine both to build even better sites AND apps.

The only thing that changed is how Microsoft positions Silverlight. But we knew that already months ago with the Team Silverlight article: http://team.silverlight.net/announcement/the-future-of-silverlight/ . No one said Microsoft is quitting on Silverlight. Please remember that!

There’s a lot of people trying to put Silverlight in a bad situation. Most of these have no idea what Silverlight is or they are afraid of the power of Silverlight. I do think it’s funny how some magazines also bend the words from MJF’s article even more and come up with titles that are just there to make some more money from their advertising contract (One known site I won't mention by name even deleted my nuanced reply, so far for honest journalism!).

Some other interesting articles:

• http://csharperimage.jeremylikness.com/2010/10/so-whats-fuss-about-silverlight.html
• http://blog.nerdplusart.com/archives/silverlight-and-html5-and-your-future
• http://wildermuth.com/2010/10/30/Post-PDC_HTML5_v_Silverlight_Debate
• http://blog.galasoft.ch/archive/2010/10/30/my-position-on-the-silverlight-debate.aspx

Feel free to comment (I won’t delete your comment ;-) ) !

On Wednesday October 27th, I gave a webinar for SilverlightShow.net. The topic in this webinar was 10 tips in Silverlight 4. The video will be online soon. Meanwhile, you can already take a look at the slides and demos below.

Slides – Demos

Last Monday, I was for the very first time at SDC in The Netherlands, the conference organized by the people behind SDN. I gave 2 presentations there, you can download the slides and demos below.

Silverlight 4 Tour de Force with a little WPF 4 sauce on top: Slides – Demos

Silverlight 4 Tips and tricks: Slides – Demos

The upcoming PDC, which starts tomorrow, is probably the most unique one ever. While there are only a 1000 attendees possible AND the event is taking place in Redmond, more people than even will be able to watch it live. This is truly the first world-wide PDC.

If you want to watch the keynote live, you can do so using http://bit.ly/akeK7Q .
Also, you can join us at the Microsoft building where we are holding a local PDC event (Visug and Microsoft). Still a few seats open here so register if you want to join via EventDetail.aspx-EventID=1032463933&Culture=en-US .
More on PDC here in the coming days of course!

Light up your Silverlight skills with the all-new Global Silverlight Firestarter!

What is the Silverlight Firestarter?

-          An Event: A one day, global, live streamed and on demand event keynoted by Scott Guthrie

-          Training: New self-paced labs and walk through videos

-          Interactive: Got questions? Get your answers! Watch live and ask the Silverlight product team questions during the event.

-          Why Silverlight? Silverlight is Microsoft’s strategic development platform for building interactive applications across desktop, phone, and the browser.

Something for Everyone

-          Just starting out with Silverlight? Watch our On-Ramp sessions and work on hands on labs to get you started.

-          Already Building business applications? Watch the event live and learn how to create compelling business applications with Silverlight.

-          Got questions? Engage with the Silverlight product team live or in person with our interactive chat.

When
Register
How Much?

December 2, 2010 8am to 5pm PT
Register Online, Now!
Nothing! This is a free event

After the live event keep fueling the fire!

Dive deeper with additional hands on labs and videos that build on the live session content, accelerating you ahead of the crowd.

-          Watch the entire event on demand!

-          Plus, new self-paced labs and walk through videos

-          On Ramp Labs (100 level)

• Hands on labs specifically focused on helping new developers get up to speed quickly on Silverlight
• Do you know WinForms? HTML? ASP.NET? Want to learn Silverlight? We have a lab for you!

-          Building Better Business Apps (200-300 level)

• Hands on labs focused on taking advantage of Silverlight to build real world business applications
• Apply Data Strategies, Patterns, Out of Browser, RIA Services, and much more using Silverlight

-          Turnabout is fair play! Watch a video of our experts doing the labs themselves.

F I R E S T A R T E R     L I V E     A G E N D A

8:00 am
Silverlight Firestarter Keynote
Scott Guthrie

9:00 am
Masterful Data Strategies with Silverlight and WP7
Jesse Liberty

10:00 am
15 minute break

10:15 am
Roll Out Your Business Apps Today with RIA Services
Pete Brown

11:15 am
MVVM: Why and How? Tips and Patterns using MVVM and Service Patterns
John Papa

12:15 pm
Lunch break

1:00 pm
Silverlight Today and Tomorrow (Special Guest Panel)
Panel

1:30 pm
Building Real World Silverlight Apps
Tim Heuer

2:30 pm
15 minute break

2:45 pm
Tune Your Application: Profiling and Performance Tips
Mike Cook & Jossef Goldberg

3:45 pm
Killer Performance Tips for Silverlight Windows Phone 7
Jaime Rodriguez

After Party!

-          Blog and tweet to spread the word about the Firestarter!

-          Ask people to add the Twitter hash tag #slfs10 to their tweets

-          Use the banners and blog bling (attached)

Questions

Got questions? Ask slfs@microsoft.com

This Wednesday, on October 27th, I’ll be doing another webinar for SilverlightShow.net. Like always, these are free to attend. The topic for this webinar is “10 Tips in Silverlight”. If you attend, you can win a copy of my book, Silverlight 4 data and services cookbook (which keeps getting great reviews by the way :) ).

The tips that you’ll see are the following:

1. Behaviors
2. PathListBox
3. Binding tricks
4. INavigationContentLoader
5. Debugging services
6. Securing service communication
7. Leveraging ASP.NET membership
8. Uploading and downloading files
9. Downloading functionality on-demand
10. Bag of tricks

Registration is free but required, you can register here.

Last week, I did a webcast on MEF (Managed Extensibility Framework) for SilverlightShow.net, one of the largest Silverlight communities. The webcast is now online and can be viewed on-demand here.

Haven’t had the chance to attend the Belgian REMIX10 this year? Or you were there but of course could see all the parallel sessions at once? Then, I have the ideal solution for you: all sessions and interviews can now be watched online from www.remix10.be.

Here are my interview and session:
Interview
Session

After some time, I’m glad to announce that the official, world-renowned Silverlight Tour is coming to Belgium, the Netherlands, the UK and more countries, organized byOrdina Belgium. The second thing I’m glad about is that I’ll be the instructor for this training!

The most important link for all this: http://bit.ly/SilverlightTour, where you can find all information, registration and prices. Currently, we have an early bird offering ending in a few weeks for the first batch of sessions.

What is Silverlight Tour?

The Silverlight Tour Workshop is a three-day course on Silverlight 4, given all around the world throughout the USA, Asia and South-America. Ordina will organize the training in several European countries starting Q4 2010.

The training divides the content into three distinct areas: Design, Development and the Server-Side. Students should be able to develop Silverlight 4 applications once attending the workshop. The Workshop is structured with a mix of didactic lessons, demonstrations and hands-on labs.

Each student will leave the workshop having created several small Silverlight applications. This variety of learning techniques will ensure that all students become proficient in the technology quickly and in an exciting way.

Key values of Silverlight Tour

• Learning Silverlight from an expert in the technology
• Hands-on labs with Visual Studio and Blend make sure you get to apply your acquired knowledge
• Architect Silverlight applications
• Learn about LOB features such as data access and data binding

Why Silverlight?

Silverlight is Microsoft's approach to building RIA (Rich Internet Applications). The platform has since its introduction, taken the world by storm. Now at its fourth iteration, Silverlight is ready for building Line-Of-Business applications, building on the strong foundation of .NET.

Now is the time to learn Silverlight! Not only is Microsoft investing heavily in the platform, but Silverlight is also the base for Windows Phone 7, Microsoft's new mobile platform. And with WPF as the desktop variant, you can apply your knowledge on the web, on the desktop and on mobile devices.

The Silverlight Tour can help you achieve the knowledge you need to start building Silverlight applications today!

Our offering

The Silverlight Tour comes in 2 flavors, depending on your Silverlight knowledge.

If you don't have any experience with Silverlight yet, the Silverlight 4 Tour workshop is ideal for you. In this 3 day course, we are starting from scratch, teaching you the foundation for your Silverlight endeavours. After this training, you'll feel comfortable with the technology and can start building your own applications.

If you already have some experience with the platform, or you just followed the Silverlight 4 Tour, we advise you the Advanced Silverlight 4 workshop. In this 2 day training, we'll tackle the more advanced concepts such as MVVM, advanced data access and IOC.

We offer the combined course (Silverlight 4 Tour Workshop + Advanced Silverlight 4 workshop) at a reduced price.

Yesterday, I arrived back home after touring Sweden for a week. I gave presentations in Malmö, Stockholm, Örebro and Götherborg. Each session was attended by a great number of developers, all members of Swenug. The sessions were sponsored by the people at Telerik: at each session, I got to give away some cool prices from Telerik, including in each city a Telerik Ultimate Collection!

Malmo pictures

Stockholm pictures

Örebro pictures

Göthenburg pictures

In the meantime, here are the downloads for the sessions, including all demos and slide decks.

I hope to be back in Sweden very soon! If you have any questions or remarks, please let me know!

I totally forgot to upload these to my blog :)

Anyway, this is the slide deck and the demos for my talks at SiXin (the Silverlight and User Experience user group) in the Netherlands two weeks back.

Yesterday, I gave a presentation at ReMix 2010 in Belgium, the third edition of this annual Microsoft event. My talk, Building an end-to-end Silverlight 4 application – Writing your Christmas Cards with Silverlight, was focused around the new and existing features in Silverlight 4, helping developers building Silverlight Line-Of-Business applications. These included data access, data binding, hardware access, drag and drop, right-clicking, Out-Of-Browser and Trusted applications.

The slide deck can be downloaded here and the entire demo can be found here.

Dear readers, I’m excited to announce the launch of .NET Show, the Belgian podcast for .NET developers. I’ve been working on this project for some time now and today, we are launching the site AND the first episode!

What is .NET Show?

Together with Katrien De Graeve, I’ll be recording podcasts on .NET development (in the broad sense of the word, so everything related to .NET) from now on. Our goal is bringing you in contact with all corners of the Microsoft development stack, from Silverlight to Azure, from COM interop to ALM... In our podcasts, we are focusing (initially at least) on local guests and we will be doing most shows in Dutch. This way, we can differentiate ourselves from the numerous podcasts already available. The topics, while on .NET of course, can be something that the guests has been working on (a professional project, a hobby project), a technology you have been investigating, something you think that can be interesting for others to hear about etc.

The first first episode can be downloaded already. In this first episode, we are talking with Maarten Balliauw on Windows Azure and the Microsoft cloud strategy in general.
In episode 2, which we’ll put online in the coming week, I’m talking with Pieter Gheysens on ALM (Application Lifecycle Management) in Visual Studio 2010. And in episode 3, I’m sitting down with my co-author Kevin Dockx and we will be discussing WCF RIA Services in real-life projects.

If you are interested in doing a podcast, let me know! Send me a mail at dotnetshow@snowball.be and I’ll contact you. If you have any remarks or questions, send them to that address as well!

So, with that, I hope you’ll enjoy our podcasts! Head over to www.dotnetshow.be where you can find the first episode. If you want (and I know you will) to subscribe via iTunes or another podcast downloader, use this link: To add .NET Show to iTunes, go to Advanced – Subscribe to Podcast:

In the window that appears, enter the following URL: http://www.dotnetshow.be/syndication.axd:

.NET Show will now appear in your subscribed podcasts!

I’m happy to announce that Microsoft, Visug and Azug are teaming up to bring you the PDC 2010 event in Belgium! We'll have live-stream of the 2 keynotes, a Windows 7 demo fest and great fun in al all-American style!

Agenda:
17u30 – Welcome and drink
18u00 – 20u -  Watch the PDC keynote live stream on big screen
20u – 20u30 – Dinner
20u30 – 21u30 – Demofest
21u30 - 22u30 – Networking

Registration only via this link: https://msevents.microsoft.com/CUI/EventDetail.aspx?EventID=1032463933&Culture=en-US

From October 4th until October 8th, I’ll be touring through Sweden, visiting 4 user groups in 4 cities to do a mini-Silverlight roadshow. During the 4 evenings, I’ll be giving sessions on data-related stuff using Silverlight.

If you’re in the neighborhood (or live in Sweden :) ), you’re welcome to join of course. All events are free and start at 6pm. Here are the details of where I’ll be on which day:

October 4th: Malmö
Registration: http://www.swenug.se/events/skaane-silverlight-4-tour-de
Address:
Cornerstone Malmö, 
Norra Vallgatan 100
Malmö

October 6th: Stockholm
Registration: http://www.swenug.se/events/sthlm-silverlight-4-tour-de
Address:
.Net Akademien
Dalagatan 100
STOCKHOLM

October 7th: Örebro
Registration: http://www.swenug.se/events/oerebro-silverlight-4-tour-de
Address:
Cityconferencecenter
Klostergatan 23
Örebro

October 8th: Göteborg
Registration: http://www.swenug.se/events/gbg-silverlight-4-tour-de
Address:
Sigma
Lindholmspiren 9
Göteborg

I hope to meet you there!

In April, I was in the UK for speaking at the VBUG conference and I was impressed by a demo given by Josh Twist. He built using MEF and WPF a “marketplace” application. The goal of the application was mainly showing the dynamic capabilities of adding new functionality to an application through MEF (or in full, the Managed Extensibility Framework for Silverlight 4).

For a presentation I’m giving shortly, I rebuilt something similar but in Silverlight: the MEF Marketplace in Silverlight. The setup is the following: a user gets an overview of apps he purchased in the market place and can run these on demand. The market place app will download the applications available to the user after the application has started, so this app mainly is a hosting shell for the other ‘purchased” applications to run in. Of course, the sample is a demo and can be extended quite a lot. For example, in the current implementation, I hard-coded the list of purchased apps and there’s no option to buy new ones. Also, it could be extended so that when new apps are purchased, a duplex service notifies the client of this and MEF downloads the new app in the background.

But, instead of talking of what could be added, let’s take a look at what I currently built already! Here’s a screenshot of the application showing the "purchased” applications.

And here’s one of the apps (the Flickr Image search) running inside the "market place shell”.

Time for some code. Let’s begin with the market place itself.

I defined a contract interface for all applications that can be loaded in the market place, IMarketPlaceApplication.

              public
              interface IMarketPlaceApplication

{

              string ApplicationName
{ get; }

    FrameworkElement MarketPlaceIcon { get; }

    FrameworkElement MainView { get; }

}

A very easy application that will be possible to load from MEF is the HelloWorldApplication. The project structure of this app is as follows:

As you can see, there’s a class called HelloWorldApplication, which implements the IMarketPlaceApplication and 2 xaml files. The HelloWorldApplication code is shown below:

[Export(typeof(IMarketPlaceApplication))]

publicclass HelloWorldApplication:
IMarketPlaceApplication

{

#region IMarketPlaceApplication
Members

publicstring ApplicationName

    {

        get { return"Hello
MEF world"; }

    }

    [Import(typeof(Icon))]

public FrameworkElement
MarketPlaceIcon

    {

        get;

        set;

    }

    [Import(typeof(HelloWorldView))]

public FrameworkElement
MainView

    {

        get;

        set;

    }

#endregion

}

This is our first encounter with MEF. The first line uses the Export attribute. This class is saying that it is available for someone to use, when someone requests an instance of IMarketPlaceApplication. A bit further, we are using the Import attribute on both the MarketPlaceIcon and the MainView. Here we are saying: MEF, search us a class that’s exporting itself as type Icon and HelloWorldView respectively.

These 2 latter instances will be inserted by MEF upon executing the application, that is, if MEF finds the corresponding export. These exports can be found in the 2 XAML files (in the code-behind). The HelloWorldView.xaml.cs code is shown next. Note the Export attribute: we’re telling to MEF that this type can be used where an Import is requested of the HelloWorldView type.

[Export]

publicpartialclass HelloWorldView
: UserControl

{

public HelloWorldView()

    {

        InitializeComponent();

    }

}

The Icon.xaml.cs is pretty similar code-behind-wise (I think I invented that term here): here alse we are adding an Export attribute.

[Export]

publicpartialclass Icon
: UserControl

{

public Icon()

    {

        InitializeComponent();

    }

}

The HelloWorldApplication is at this point a stand-alone application (it compiles to its own XAP file), but we’ll now build the Market Place shell that will host this app. The code download at the end of the article contains several sample applications (a Flickr app and a Facebook app).

Similar to a real market place application, our implementation will get a list of apps you purchased previously. Only these are available to you and will be shown. To get this list, I wrote a basic Silverlight-enabled WCF service that fetches this list of available applications. This service is hosted in this case in the hosting website. The code below shows this service, which in this case returns a hard-coded list of apps (note that I have some more apps already added here).

[ServiceContract(Namespace = "")]

[AspNetCompatibilityRequirements(RequirementsMode = 

    AspNetCompatibilityRequirementsMode.Allowed)]

publicclass MarketPlaceService

{

    [OperationContract]

public List<MefApplication>
GetAvailableApplicationsForUser()

    {

returnnew List<MefApplication>()

        {

new MefApplication(){ApplicationName="Flickr
Image Search", 

                XapFileName="FlickImageSearch.xap"}, 

new MefApplication(){ApplicationName="Hello
World", 

                XapFileName="HelloWorldApplication.xap"},

new MefApplication(){ApplicationName="MEFacebook", 

                XapFileName="FacebookApplication.xap"}

        };

    }

//
Add more operations here and mark them with [OperationContract]

}

[DataContract]

publicclass MefApplication

{

    [DataMember]

publicstring ApplicationName
{ get; set; }

    [DataMember]

publicstring XapFileName
{ get; set; }

}

The service uses the MefApplication class as a helper class: it contains the name of the application and more importantly, the name of the XAP file (this could easily be replaced with a Uri to the XAP file).

In the MefMarketPlace, the Silverlight Market Place application, we can create a web reference to this service. In the App.xaml.cs, I add a call to a new method, DownloadMyApplicationList():

privatevoid Application_Startup(object sender,
StartupEventArgs e)

{

    DownloadMyApplicationsList();

this.RootVisual
= new MainPage();

}

This new method makes the service call to get a list of available XAPs that I can use (apps that I purchased).

void DownloadMyApplicationsList()

{

    AggregateCatalog = new AggregateCatalog();

    container = new CompositionContainer(this.AggregateCatalog);

    CompositionHost.Initialize(container);

    MarketPlaceService.MarketPlaceServiceClient client = 

new MarketPlaceService.MarketPlaceServiceClient();

    client.GetAvailableApplicationsForUserCompleted += 

new EventHandler<MarketPlaceService.GetAvailableApplicationsForUserCompletedEventArgs>

            (client_GetAvailableApplicationsForUserCompleted);

    client.GetAvailableApplicationsForUserAsync();

}

void client_GetAvailableApplicationsForUserCompleted(object sender, 

    MarketPlaceService.GetAvailableApplicationsForUserCompletedEventArgs e)

{

if (e.Error
== null)

    {

        AvailableApplicationsForUser = e.Result;

        InitializeCatalog();

    }

}

In the callback method of the service, I call InitializeCatalog(). MEF has the concept of Catalogs: a Catalog can be used to tell MEF where it has to look for Parts. Several types of catalogs exist in MEF for Silverlight: the TypeCatalog, the AssemblyCatalog, the DeploymentCatalog and the AggregateCatalog. A TypeCatalog basically allows us to register a specific type with MEF: if I want MEF to know about a certain Export, I can register it in a TypeCatalog. An AssemblyCatalog tells MEF to look for parts in a specific assembly. The DeploymentCatalog allows us to specify a XAP file and MEF will look in the assemblies therein for parts. It also allows us to asynchronously download a XAP file. An AggregateCatalog can contain any number of other catalogs and more catalogs can be added at any time.

By default, if we don’t specify a Catalog for our application, MEF looks at the current XAP file and for each assembly it finds, it creates an AssemblyCatalog. It then combines these with an AggregateCatalog. That means that we can omit creating a catalog in our application: in this case, MEF will create a default one for us, with something similar to this code:

void InitializeCatalog()

{

    AggregateCatalog catalog = new AggregateCatalog();

foreach (var
deployedPart in Deployment.Current.Parts)

    {

        StreamResourceInfo resourceInfo = 

            Application.GetResourceStream(new Uri(deployedPart.Source,
UriKind.Relative));

        Assembly assembly = deployedPart.Load(resourceInfo.Stream);

        catalog.Catalogs.Add(new AssemblyCatalog(assembly));

    }

    CompositionHost.Initialize(catalog);

}

Back to our application. If we look at the available catalogs in MEF, we can see that the DeploymentCatalog is a good candidate for what we need: we can use it to download a XAP file (the application that we want to load). After that, we can add each DeploymentCatalog to an AggregateCatalog. MEF will then make these available in our application and we can run the downloaded applications.

In code, this gives the following:

private CompositionContainer
container;

void InitializeCatalog()

{

foreach (var
item in AvailableApplicationsForUser)

    {

        DeploymentCatalog deploymentCatalog = 

new DeploymentCatalog(item.XapFileName);

this.AggregateCatalog.Catalogs.Add(deploymentCatalog);

        deploymentCatalog.DownloadCompleted += (s, e) =>

        {

//extend
to give meaningful error handling

if (e.Error
!= null)

                MessageBox.Show(e.Error.Message);

        };

        deploymentCatalog.DownloadAsync();

    }

    container.ComposeParts(this);

}

You can see that I use a CompositionContainer here. The container is well, like the word says it, a container where MEF puts all the parts, shakes it up and creates/composes parts.

We now have the code that runs when we start the application: it gets a list of all the applications we can use over the service and then it downloads the XAP files of these apps asynchronously. Each XAP file is downloaded using a DeploymentCatalog and these are added to an AggregateCatalog. This now makes our downloaded applications available to run.

Let’s now take a look at the UI where we’ll run the apps from. The following screenshot shows the UI:

The “Load my apps'” button on the top right will execute a command on the viewmodel that will load all available applications in the ListBox on the left.

When clicking on the “Load app” button, the selected application (here the Flickr app) is loaded:

Clicking the “Home” button unloads the app and returns us to the list screen.

The complete XAML listing can be found in the code download. The most important part is shown below. Note that there’s a ContentPresenter used here and it’s bound to the MainView property of the SelectedApplication. The latter is a property exposed on the viewmodel (see further). If no view/app is selected, this ContentPresenter won’t be visible and we’ll see the default UI again.

<Gridx:Name="LayoutRoot"Background="Black">

<Grid.RowDefinitions>

<RowDefinitionHeight="*"></RowDefinition>

<RowDefinitionHeight="60"></RowDefinition>

</Grid.RowDefinitions>

<Grid>

        ...

</Grid>

<ContentPresenterContent="{Binding
SelectedApplication.MainView}">

</ContentPresenter>

<ButtonGrid.Row="1"Content="Home"Margin="10"Background="#FFABE3FF"

Command="{Binding
HomeCommand}"BorderBrush="#FF00AAFF"

Style="{StaticResource
ButtonStyle1}"

Width="130"Height="40"HorizontalAlignment="Center"

VerticalAlignment="Center"></Button>

</Grid>

Time to look at the viewmodel now. Probably the most important part here is the ObservableCollection<IMarketPlaceApplication>:

[ImportMany(AllowRecomposition=true)]

public ObservableCollection<IMarketPlaceApplication>
Applications

{

    get

    {

return _applications;

    }

}

The ListBox in the UI is bound to this collection and since it’s an ObservableCollection, the UI will reflect changes to this collection. That’s important here, since the list of available apps won’t be known after the shell contacted the service. Note that the collection property is attributed with the ImportMany attribute. This is a sign for MEF that more than one part that is exposing itself with the same Export attribute (same type) is allowed. By default, this isn’t allowed since MEF wouldn’t know which one to use. Here, we want the ImportMany since we know that more than one app will be available and they all need to be exported as an IMarketPlaceApplication. Another important thing to note here is the AllowRecomposition option we used here. AllowRecomposition tells MEF that if during the run of the app more Exports become available for this Import, it’s OK to add them, in other words, to rebuild the composition.

The ContentPresenter in the UI bound to SelectedApplication.MainView. The SelectedApplication property is shown next.

private IMarketPlaceApplication
_selectedApplication;

public IMarketPlaceApplication
SelectedApplication 

{

    get

    {

return _selectedApplication;

    }

    set

    {

        _selectedApplication = value;

        NotifyPropertyChanged("SelectedApplication");

    }

}

NotifyPropertyChanged is a simple method that raises the PropertyChanged event of the INotifyPropertyChanged interface.

privatevoid NotifyPropertyChanged(string p)

{

if (PropertyChanged
!= null)

    {

        PropertyChanged(this, new PropertyChangedEventArgs(p));

    }

}

The “Load apps” button in the UI is bound to the LoadAppsCommand. I use the MVVM Light RelayCommand here. In the execute code of the ICommand, I ask MEF to satisfy the Imports of the current class (the viewmodel). This basically tells MEF to look at the catalogs and bring all the Export(typeof(IMarketPlaceApplication)) into the ImportMany.

public RelayCommand
LoadAppsCommand

{

    get

    {

if (_loadAppsCommand
== null)

        {

            _loadAppsCommand = new RelayCommand(

                    () =>

                    {

                        CompositionInitializer.SatisfyImports(this);

                        loaded = true;

                    },

                    () =>

                    {

if (loaded)

returnfalse;

returntrue;

                    }

                );

        }

return _loadAppsCommand;

    }

}

The LoadSelectedApplicationCommand and the HomeCommand respectively set the SelectedApplication property to the selected application in the list or null.

public RelayCommand<IMarketPlaceApplication>
LoadSelectedAppCommand

{

    get

    {

if (_loadSelectedAppCommand
== null)

        {

            _loadSelectedAppCommand = new RelayCommand<IMarketPlaceApplication>(

                    (a) => 

                    { 

                        SelectedApplication = a; 

                    }

                );

        }

return _loadSelectedAppCommand;

    }

}

public RelayCommand
HomeCommand

{

    get

    {

if (_homeCommand
== null)

        {

            _homeCommand = new RelayCommand(

                    () =>

                    {

                        SelectedApplication = null;

                    }

                );

        }

return _homeCommand;

    }

}

With that, we have successfully implemented the MEF Marketplace. As said in the very beginning, this can be extended quite a lot. Add a duplex service and a buying system that pushes a message to the client and trigger the client to download the linked XAP file is a nice way to start. The complete file can be downloaded below.

Enjoy!

Code download: MefMarketPlace.zip (868.99 KB)