Microsoft Patterns & Practices: Prism for the Windows Runtime – My favourite resources

As you may know, the Microsoft Patterns & Practices team has recently released the final version of  “Prism for Windows Runtime“, available for download here on CodePlex.

Prism for Windows Runtime

This project contains a complete guidance for building Windows Store apps using C# and XAML and includes the following resources:

Big kudos to all the p & p team: they did an amazing job and I personally felt honored to have the possibility of providing feedback whilst the project was in development.

This is really a great guidance for building Windows Store applications that can be easily tested, maintained and extended: every developer building complex apps will benefit from it.

Other useful links:

Happy coding everyone!

Using the Multi-Touch Behavior in a Windows Phone 7 Multi-Page application

In these days I’m receiving several questions in the Multi-Touch Behaviors forums about enabling Multi-Touch manipulations in Windows Phone applications composed by more than one page.

Today I’ve modified the available sample inserting an additional page containing an image enabled for translation, rotation, zoom and inertia via the usual “MultiTouchBehavior“:

Starting from release 0.6.1 it’s now possible to use the Behavior in different pages of the application, in this way enabling multi-touch in different elements of a Windows Phone 7 application.

As usually the sample code is available for download on, check out the Visual Studio solution “SilverlightWP7MultiTouch.sln” which contains all necessary libraries.

Happy Silverlighting!

TechDays WPC 2010: I’ll be there! Speaking about Silverlight, Multi-Touch and Natural User Interfaces

This year I’ll be presenting about “Silverlight, Multi-Touch and Natural User Interfaces” at the Techdays WPC 2010 conference in Milan on November, 25 2010.

The same day I’ll be also at the MVP booth, if you’re attending the conference come and say Hi! 🙂

Happy Silverlighting!

Windows Phone 7, Multi-Touch Behaviors and the Surface samples for Silverlight

I’ve just finished some experiments using the Windows Phone 7 emulator and the “Microsoft Surface Manipulations and Inertia Sample for Microsoft Silverlightin order to enable Multi-Touch gestures using Blend Behaviors:


This new implementation, now available for download in the Expression Gallery, permits to enable Multi-Touch gestures (the usual translation, rotation, zoom and inertia) on separate User Controls available in the same container.

In this way you can apply distinct Multi-Touch manipulations (inertia included) to single elements using a single code in xaml:



Alternatively you can use Blend inserting a reference to the project MultiTouch.Behaviors.Silverlight.WP7 and then dragging the MultiTouchManipulationBehavior from the Assets section to the  control to be touch-enabled:

Multi-Touch Behavior Blend



This one has been an interesting exercise in porting code written for Silverlight to Windows Phone: I had only to create a Windows Phone 7 project and add to it the code already available for the Silverlight version and all worked well quite quickly.


At this time the behavior works only in the fixed Portrait orientation of Windows Phone: if you change to Landscape the manipulation doesn’t work well. I’ll have to investigate further and currently I don’t have a physical device to test (I’d really love to have a device to try it :)).

Happy Silverlighting!

Windows Phone 7 Multi-Touch Behavior videos #wp7dev

Some time ago I’ve started a Codeplex project dedicated to multi-touch, available on Codeplex at

The goal of this project is to provide an unified interface for Silverlight, WPF and Windows Phone 7 in order to provide multi-touch support using a visual approach via the concept of Behavior available in Expression Blend.

Recently I had the honor to welcome in the project a pillar of the Silverlight community, Laurent Bugnion, who is working on the Windows Phone 7 version of the Behavior:

Laurent has just published on his blog two awesome videos to get started with this new Behavior, and has created a specific section on his site to announce updates and publish content.

A special thanks to Pete Blois of the Expression Blend team for his help and contributions.

Stay tuned as we’ll be posting updates very soon 🙂

Happy Silverlighting!

Slides and Code from my Silverlight 4 – MEF webcast

Here you can find the sample code and slides (in italian) from my webcast around Silverlight 4 and MEF for the local XEdotNET user group.

The samples contain the following topics:

  • Simple composition using the CompositionInitializer;
  • Multiple Exports;
  • Metadata;
  • Custom Attributes;
  • Dynamic object creation with ExportFactory;
  • Simple MVVM example using MEF;
  • MEF, MVVM and PRISM EventAggregator;
  • Dynamic XAP loading using DeploymentCatalog;
  • MEF, MVVM and Blend Sample Data.

Hope this helps and Happy Silverlighting!

Silverlight 4, MEF and MVVM: MEFModules, Dynamic XAP Loading and Navigation Applications

In the last example I’ve implemented a new “MEF Module” organized with a MVVM approach and using Prism Event Aggregator to exchange messages.

This new module could be used to partititon the application in several XAPs composed dynamically at run-time using MEF, the new DeploymentCatalog and the Navigation features available in Silverlight.

To start I’ve created a new “Silverlight Navigation Application” which produces a complete application with ready-to-use navigation and localization.

Then I’ve inserted a new “Silverlight User Control” inside the “Views” folder and named it “MEFModuleContainer“: this one is called by the navigation framework and is responsible to load dynamically the module using the MEF “DeploymentCatalog“.

This is the XAML of the container:

<StackPanel x:Name="ContentStackPanel">
    <TextBlock x:Name="HeaderText" Style="{StaticResource HeaderTextStyle}"
               Text="MEF Module container"/>
    <TextBlock x:Name="ContentText" Style="{StaticResource ContentTextStyle}"
               Text="MEF content"/>
    <ItemsControl x:Name="content"/>

Our “MEF Module” is hosted in a “ItemsControl” using the “Items” property:

public MEFModuleContainer()



public IDeploymentCatalogService CatalogService { get; set; }

[ImportMany(AllowRecomposition = true)]
public Lazy<UserControl>[] MEFModuleList { get; set; }

#region IPartImportsSatisfiedNotification Members

public void OnImportsSatisfied()


In order to use the DeploymentCatalog, it’s necessary to define an interface IDeploymentCatalogService (read this post by Glenn Block for more information about it):

public interface IDeploymentCatalogService
    void AddXap(string uri, Action<AsyncCompletedEventArgs> completedAction = null);
    void RemoveXap(string uri);

and implement it in the class “DeploymentCatalogService“:

public class DeploymentCatalogService : IDeploymentCatalogService
    private static AggregateCatalog _aggregateCatalog;

    Dictionary<string, DeploymentCatalog> _catalogs;

    public DeploymentCatalogService()
        _catalogs = new Dictionary<string, DeploymentCatalog>();

    public static void Initialize()
        _aggregateCatalog = new AggregateCatalog();
        _aggregateCatalog.Catalogs.Add(new DeploymentCatalog());

    public void AddXap(string uri, Action<AsyncCompletedEventArgs> completedAction = null )
        DeploymentCatalog catalog;
        if (!_catalogs.TryGetValue(uri, out catalog))
            catalog = new DeploymentCatalog(uri);
            if (completedAction != null)
                catalog.DownloadCompleted += (s, e) => completedAction(e);
                catalog.DownloadCompleted += catalog_DownloadCompleted;

            _catalogs[uri] = catalog;

    void catalog_DownloadCompleted(object sender, AsyncCompletedEventArgs e)
        if (e.Error != null)
            throw e.Error;

    public void RemoveXap(string uri)
        DeploymentCatalog catalog;
        if (_catalogs.TryGetValue(uri, out catalog))

The DeploymentCatalogService is initialized during the Application startup in this way:

private void Application_Startup(object sender, StartupEventArgs e)
    //Initialize the DeploymentCatalogService for MEF
    this.RootVisual = new MainPage();

When the user clicks on the Navigation bar, the container is loaded and filled with the content of the external XAP, all managed by MEF:

So we have a Navigation application which can dynamically load external “MEFModules” organized with a MVVM approach, contained in external XAPs and using an Event Aggregator to exchange messages, all managed by MEF.

This application can be easily extended inserting WCF RIA Services and/or Blend sample data for the design mode.

As usually the sample code is available for download here and will be soon available in the CodePlex project “MEF MVVM” –

Happy Silverlighting!

Multi-Touch enabling Silverlight Simon using Blend behaviors and the Surface sample for Silverlight

I have already blogged about using Blend behaviors to add Multi-Touch gestures and inertia effects to a generic Silverlight user control, so I wanted to use the same approach to add the same behaviors to the CodePlex project Simon.

I think that inserting multi-touch manipulation effects to a Silverlight application using Blend behaviors is an elegant way which makes the code very clear and readable.

To start you need to download the Multi-touch manipulation and inertia behavior (wow, more than 7000 downloads, great feedback! :)), which I already published on the Expression site.

This behavior is based on the code available in the Microsoft Surface Manipulations and Inertia Sample for Microsoft Silverlight, in my opinion the best example available for using multi-touch in Silverlight at this time.

The solution available contains a project named “MultiTouch.behaviors.Silverlight” which must be included in your application to enable the multi-touch functionalities.

To make the Silverlight/Blend Behavior work with Simon I’ve modified some code relative to the Zoom gesture in order to use a ScaleTransform (check out the source code on CodePlex:

To use the Behavior in XAML just add a reference to the “MultiTouch.Behaviors.Silverlight” project and use the following code:

<UserControl x:Class="SimonSilverlight.MainPage"
    xmlns:interactivity="clr-namespace:System.Windows.Interactivity; assembly=System.Windows.Interactivity"
    xmlns:multitouch="clr-namespace:MultiTouch.Behaviors.Silverlight; assembly=MultiTouch.Behaviors.Silverlight">
    <uc:Simon x:Name="Says">
            <multitouch:MultiTouchManipulationBehavior InertiaEnabled="True" TouchRotateEnabled="True"
                       TouchScaleEnabled="True" TouchTranslateEnabled="True"/>

Since we are using a Blend Behavior, we can also open the solution in Expression Blend, select the “MultiTouchManipulationBehavior” from the “Assets” section and drag it over the Simon control:

Happy Silverlighting!

Silverlight 4, MEF and MVVM: EventAggregator, ImportingConstructor and Unit Tests

I had recently the possibility to use MEF and Silverlight in a sample project together with Prism, this is for sure a great combination of frameworks for bulding applications using maintainable and extensible code. I don’t think that using MEF excludes the usage of Prism and vice versa,  the choice should be pondered and analyzed accordingly to the problem to solve.

Starting from the previous experiments, I decided to refactor and cleanup the MVVM approach in order to:

  • obtain simpler code;
  • inserting an EventAggregator managed by MEF to exchange messages;
  • maintaining the Visual Studio designer/Blend support;
  • trying a simple unit test using the framework available in the Silverlight Toolkit.
  1. Using the EventAggregator

The first step is inserting in the project the Prism EventAggregator downloading the “Microsoft.Practices.Composite.dll” and “Microsoft.Practices.Composite.Presentation.dll” libraries from the Prism site on Codeplex.

It’s now possible to make available in the application an instance of it using this syntax:

public class EventAggregatorProvider
   public IEventAggregator eventAggregator { get { return new EventAggregator(); } }

In this way we are able to import it in the ViewModel class using an [ImportingConstructor] attribute:

public MainPageViewModel(IEventAggregator eventAggregator, IDataItemsService dataItemsService)
   _eventAggregator = eventAggregator;
   _dataItemsService = dataItemsService;

When an [ImportingConstructor] is found, MEF looks for an [Export] for each parameter available in the constructor, in this case we must have exported an “IEventAggregator” and an “IDataItemsService”.

We are now able to access the instance of the EventAggregator and Publish/Subscribe to events using a syntax like:

//Call the Service

//Subscribe to the "DataItemsReceivedEvent"

_eventAggregator. GetEvent(). Subscribe(
    dataItemsReceived =>
        this.dataItems = dataItemsReceived;

In this case we are receiving the result of the async calls via the EventAggregator and a DataItemsReceivedEvent:

public class DataItemsReceivedEvent : CompositePresentationEvent {  }

DataItemsService code publishing the Event:

//Initialize the collection
DataItemWcfService.DataItemServiceClient svc = new DataItemWcfService.DataItemServiceClient();
svc.GetDataItemsCompleted += (s1, e1) =>
    if (e1.Result != null)
        var dataItems = new DataItems();
        e1.Result.ToList().ForEach(d =>
            dataItems.Add(new DataItem() { Description = d.Description });

        //Publish the DataItems
        _eventAggregator. GetEvent(). Publish(dataItems);

        isLoading = false;
isLoading = true;

2. Maintaining the Visual Studio designer/Blend support

In the previous experiments I enabled design-time data by inserting a new ViewModel class which can create some confusion, so I decided to skip this step and using a unique ViewModel following this approach:

  • the ViewModel parameterless constuctor contains the initialization for data to be used during design time and tests;
  • the other constructor marked with the MEF [ImportingConstructor] attribute enables initialization of services and event aggregator.
public MainPageViewModel(IEventAggregator eventAggregator, IDataItemsService dataItemsService)
    _eventAggregator = eventAggregator;
    _dataItemsService = dataItemsService;

3 – Unit Test

To verify the approach described, I’ve inserted a new “Silverlight Unit Test project” to the solution (note that the “Silverlight Toolkit” must be installed to use this feature) and then a simple Test method containing the following code:

public class Tests
    [Description("Test the creation of a ViewModel and the initialization of Design/Test Data")]
    public void TestViewModelCreation()
        var vm = new MainPageViewModel();
        Assert.AreEqual(vm.dataItems.Count, 2);

Since MEF is only used to compose run-time Parts, I’m not using it in the Unit Tests.

So we have now a new piece of code, which I’ve called a “MEFModule” organized with a MVVM approach and ready for design-time support, unit tests and extensibility: ready to be inserted in a Navigation applicationdynamically loaded and enabled for design time using Blend Sample Data, stay tuned.

The source code is available for download here.

Happy Silverlighting!

A Silverlight / Expression Blend behavior to add Multi-Touch Manipulation and Inertia

I’ve updated the behavior available in the Expression Community gallery adding Multi-Touch manipulation (translation, rotation and zoom) and inertia effects using code from the Surface Manipulations and Inertia Sample for Microsoft Silverlight.

To enable Multi-Touch in your code simply download the behavior from here, add the project “MultiTouch.Behaviors.Silverlight” to a Visual Studio solution and then enable the gestures in XAML:

<UserControl x:Class="SilverlightMultiTouch.MainPage"
xmlns:interactivity="clr-namespace:System.Windows.Interactivity; assembly=System.Windows.Interactivity"
xmlns:behaviors="clr-namespace:MultiTouch.Behaviors.Silverlight; assembly=MultiTouch.Behaviors.Silverlight"

  <Image Source="Images/Desert.jpg">
         <behaviors:MultiTouchManipulationBehavior InertiaEnabled="True" TouchRotateEnabled="True" TouchTranslateEnabled="True" TouchScaleEnabled="True"/>

  <Image Source="Images/Jellyfish.jpg">
         <behaviors:MultiTouchManipulationBehavior InertiaEnabled="True" TouchRotateEnabled="True" TouchTranslateEnabled="True" TouchScaleEnabled="True"/>

The MultiTouchManipulationBehavior also contains some dependency properties (TouchRotateEnabled, TouchTranslateEnabled, TouchScaleEnabled and InertiaEnabled) to enable the corresponding gestures.

The example contains Multi-Touch manipulations applied to some Image controls and a Smooth streaming player of the Silverlight Media Framework.

I’ve also posted to CodePlex a sample using WPF 4 based on the article “Introduction to WPF 4 Multitouch” by Jaime Rodriguez.

Hope this helps and Happy Silverlighting!