posts from 2009

Silverlight Behaviors and Commands

By Fons Sonnemans, 21-12-2009

A few months ago I wrote an blog post about a Silverlight 3.0 LetItSnowBehavior. This Behavior can be used to add a Snow effect to a Canvas. Very usefull if you want to create a christmas card.

This behavior was always showing you falling snow flakes. You couldn't stop and (re)start the gameloop. The best way to implement this is by adding Commands to the behavior. This allows you to select one or more triggers to Start or Stop the gameloop. I have added the Start and Stop properties of the type ICommand to the LetItSnowBehavior class. In the constructor I have initialized these properties with new ActionCommand objects (Microsoft.Expression.Interactions.dll) and delegates to the OnStop() and OnStart() methods. Triggers attached to these commands will execute the these methods.

public class LetItSnowBehavior : Behavior<Canvas> {


    private DispatcherTimer _gameLoop = new DispatcherTimer();


    public LetItSnowBehavior() {

        // Create Commands

        this.Start = new ActionCommand(this.OnStart);

        this.Stop = new ActionCommand(this.OnStop);


        // Init timer

        _gameLoop.Interval = new TimeSpan(0, 0, 0, 0, 10);

        _gameLoop.Tick += new EventHandler(gameLoop_Tick);




    public ICommand Start { get; private set; }


    public ICommand Stop { get; private set; }


    private void OnStart() {




    private void OnStop() {





You can use Expression Blend to attach triggers to the Commands. Select the LetItSnowBehavior object and open it properties. Click the + button for the Start property and select an EventTrigger. Select the 'buttonStart' as source and the 'Click' as event. You can even add multiple triggers to the command.

Set Triggers on LetItSnowBehavior in Expression Blend 3.0

You can download the code from here.

Watch my Silverlight Christmas card

By Fons Sonnemans, 20-12-2009

Click the following image to see my Christmas card which I have created using Silverlight 3.0 and Expression Blend.

Click to view this Christmas card

I didn't have to write any line of  C# code. I only re-used some of my existing behaviors: LetItSnowBehavior and ControlMediaElementAction.

Tags: XAML, Silverlight

Beschikbaar voor Silverlight projecten

By Fons Sonnemans, 7-12-2009

Op dit moment ben ik als Silverlight ontwikkelaar op zoek naar een project. Bent u op zoek naar een ervaren silverlight specialist/architect neem dan contact met mij op. Zie ook mijn CV voor extra infromatie over mij.

Tags: Work

Simple ReportDocument for Silverlight 4

By Fons Sonnemans, 25-11-2009

I have written an Simple Report Library for Windows Forms applications a few years ago. The new Printing API makes it possible to create a similar solution for Silverlight 4.

You create a report by instantiating a new ReportDocument object. You can set the Title and the SubTitle. Next you add Paragraphs (FrameworkElements) to the report. Finally you Print the report.

ReportDocument r = new ReportDocument() {

    Title = "Test Title",

    SubTitle = "Test SubTitle",


for (int i = 0; i < 40; i++) {

    var tb = new TextBlock() {

        Text = "Test text " + i,

        FontSize = i + 10,





This prints the following Test Title.pdf if you print it to a PDF writer.

Test Title.pdf

The real magic is in the dp_PrintPage event handler of the ReportDocument class. The Header and the Paragraphs are added to a StackPanel. Before a paragraph is added the height (actual or the measured desired) is compared with the available space. If it doesn't fit the page is full and ready to be printed. The PageVisual is set to the StackPanel. The next page will continue with the current paragraph.

private void pd_PrintPage(object sender, PrintPageEventArgs e) {


    if (_panel.Children.Count == 0) {


    } else {

        // remove all except header

        while (_panel.Children.Count > 1) {




    _visual.Height = e.PrintableArea.Height;

    _visual.Width = e.PrintableArea.Width;

    double totalHeight = e.PrintableArea.Height - this.Margin.Top - this.Margin.Bottom;

    double totalWidth = e.PrintableArea.Width - this.Margin.Left - this.Margin.Right;

    double height;

    if (_header.ActualHeight > 0) {

        height = Header.ActualHeight;

    } else {

        Header.Measure(new Size(totalWidth, totalHeight));

        height = Header.DesiredSize.Height;


    while (_currentParagraphIndex < Paragraphs.Count) {

        var paragraph = Paragraphs[_currentParagraphIndex];

        if (paragraph.ActualHeight > 0) {

            height += paragraph.ActualHeight;

        } else {

            var size = new Size(totalWidth, totalHeight - height);


            height += paragraph.DesiredSize.Height;


        if (height > totalHeight) {

            // doesn't fit anymore






    e.PageVisual = _visual;

    e.HasMorePages = _currentParagraphIndex < Paragraphs.Count;


I hope you like it. I will discuss creating custom headers in a next post. You can download the code from Codeplex.

SilverlightXP 2.0 release

By Fons Sonnemans, 24-11-2009

Visit SilverlightXP

SilverlightXP is a web application where Silverlight Developers and Designers can post links to controls, resources and other interesting information about Microsoft Silverlight.


SilverlightXP is a collaboration between Loek van den Ouweland and Fons Sonnemans. The goal was to create a great User Experience for the Silverlight Community when they search for the latest and greatest stuff about Silverlight.


SilverlightXP is a Silverlight 3 application created with Visual Studio 2008, Expression Design 3 and Expression Blend 3. Used techniques include .NET RIA services and LINQ. A combination of URL rewriting, Silverlight Navigation Framework and ASP.NET SEO-optimization was used for optimal Google integration.


SilverlightXP was built for all of us in the Silverlight Community and we would love to hear from you. If you have ideas, comments, found errors or other things you would like to share with us, please send an email to

Silverlight Flip Clock

By Fons Sonnemans, 4-11-2009

I have created a simple Flip Clock using Silverlight 3 and Expression Blend 3. It uses some simple animations to flip the hours, minutes and seconds. I hope you like it.

Get Microsoft Silverlight

You can download the sourcecode from here.

Control a MediaElement using a custom Behavior

By Fons Sonnemans, 11-10-2009

Controlling a MediaElement in Silverlight isn't difficult. You use the Play(), Stop() and Pause() methods in your code. I have written the 'ControlMediaElementAction' Behavior which makes it even easier. You don't have to write a single line of code. The ControlMediaElementAction is associated with a MediaElement. It has a ControlMediaElementOption which you can set to Play, Stop, Pause and RewindAndPlay. The Invoke() methods controls (Plays, Stops, Pauses and RewindAndPlays) the AssociatedObject (MediaElement).

public class ControlMediaElementAction : TriggerAction<MediaElement> {


    protected override void Invoke(object o) {

        switch (ControlMediaElementOption) {

            case ControlMediaElementOption.Play:



            case ControlMediaElementOption.Stop:



            case ControlMediaElementOption.Pause:



            case ControlMediaElementOption.RewindAndPlay:

                this.AssociatedObject.Position = TimeSpan.Zero;








    public ControlMediaElementOption ControlMediaElementOption { get; set; }




public enum ControlMediaElementOption {

    Play, Stop, Pause, RewindAndPlay


You assign a ControlMediaElementAction to a MediaElement. In Expression Blend you drag it from you Asset tab and drop it on a MediaElement. Then you can select your trigger and set all other properties from the Properties tab.

ControlMediaElementAction in Blend 3.0

In the following example I have 3 ControlMediaElementAction assigned to a MediaElement. The first is triggerd by the 'Click' event of 'buttonPlay' and uses the 'Play' option. The second is triggerd by the 'Click' event of 'buttonPause' and uses the 'Pause' option. The third is triggerd by the 'MediaEnded' event of the MediaElement and uses the 'RewindAndPlay' option, making the movie loop.







    Width="640" Height="480">


    <Grid x:Name="LayoutRoot" Background="White">

        <MediaElement x:Name="SL_wmv" Height="200" HorizontalAlignment="Left"

                 Margin="160,40,0,0" Width="160" Source="/SL.wmv"

                 Stretch="Fill" AutoPlay="False">


                <i:EventTrigger SourceName="buttonPlay" EventName="Click">



                <i:EventTrigger SourceName="buttonPause" EventName="Click">




                <i:EventTrigger EventName="MediaEnded">






        <Button x:Name="buttonPlay" Height="40" Margin="160,0,0,160"

               Width="160" Content="Play"/>

        <Button x:Name="buttonPause" Height="40" Margin="160,0,0,80"

               Width="160" Content="Pause"/>



You can download the sourcecode here.


By Fons Sonnemans, 1-9-2009

I'm proud to announce the Silverlight website. It is a web application where Silverlight Developers can post links to interesting information, controls, resources e.t.c. We invite you to submit your Silverlight resources.

Silverlight is a Silverlight 3.0 LOB application which uses a lot of the new techniques:

  • .NET Ria Services
  • Navigation Application (deeplinking + history)
  • Search Engine Optimization (SEO)
  • Behaviors

Silverlight XP was created by Loek van den Ouweland and me, and is currently at version 1.0. We plan to add a lot of features soon. We don’t have a feedback-function yet. Please drop comments about the website by mail.

Microsoft Silverlight 3 training

By Fons Sonnemans, 17-8-2009

Silverlight is een 'cross-over browser plugin' van Microsoft die het mogelijk maakt om animaties, audio en video weer te geven in de webbrowser (zoals bijvoorbeeld Explorer, Firefox, Safari).

Silverlight bevat een subset van het .NET 3.5 Framework waarmee, vanuit een Microsoft .NET taal zoals C#, Visual Basic of .NET, een programma geschreven kan worden dat in een browser draait. Tot nu toe kon dat alleen met JavaScript of met Flash van Adobe.

Reflection IT is de eerste opleider met een Microsoft Silverlight 3 training.

Docenten Fons Sonnemans en Loek van den Ouweland verzorgen deze interactieve en praktijkgerichte trainingen voor zowel geinteresseerden als startende en meer ervaren programmeurs en grafisch vormgevers.

Silverlight 3.0 LetItSnowBehavior

By Fons Sonnemans, 14-8-2009

Silverlight 3.0 has a great new feature called Behaviors. You can use them for a lot of things, one of them is to create a SNOW effect in a canvas. I know it is not yet Christmas but I like to be prepared. If you don't know what a behavior is or how to write them read first this blog post from Andrea Boschin.

You can download the sourcecode from here.


To add the LetITSnow Behavior to your own application you first have to reference the 'ReflectionIT.Behavior.dll'. Then you can apply the LetItSnowBehavior from Expression Blend 3.0 by dragging it from the Asset Tab onto an empty Canvas. That's all.

The Canvas will now have a Interaction.Behaviors element with the LetItSnowBehavior in it.

    Width="500" Height="400">
    <Grid x:Name="LayoutRoot" Background="White">
        <TextBlock FontSize="50" HorizontalAlignment="Center" VerticalAlignment="Center"
Text="LetItSnowBehavior " /> </Grid> </UserControl>

LetItSnowBehavior implementation

The LetItSnowBehavior was created using the Behavior 'Add New Item...' template from Blend 3.0. The overriden OnAttached method generates the SnowFlakes. The SnowFlake is an Image with a random size, speed and opacity. The position is updated every 10 milliseconds using a DispatcherTimer.

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Interactivity;
using System.Windows.Threading;

namespace ReflectionIT.Behaviors {

    public class LetItSnowBehavior : Behavior<Canvas> {

        private DispatcherTimer _gameLoop = new DispatcherTimer();
        private int _numberOfFlakes = 200;

        public LetItSnowBehavior() {
            _gameLoop.Interval = new TimeSpan(0, 0, 0, 0, 10);
            _gameLoop.Tick += 
     new EventHandler(gameLoop_Tick); } protected override void OnAttached() { base.OnAttached(); this.AssociatedObject.SizeChanged +=
      new SizeChangedEventHandler (AssociatedObject_SizeChanged); } protected override void OnDetaching() { base.OnDetaching(); _gameLoop.Stop(); this.AssociatedObject.Children.Clear(); } public int NumberOfFlakes { get { return _numberOfFlakes; } set { _numberOfFlakes = value; } } private void GenerateSnowFlakes() { this.AssociatedObject.Children.Clear(); for (int i = 0; i < NumberOfFlakes; i++) { SnowFlake flake = new SnowFlake(i, this.AssociatedObject.ActualHeight,
     this.AssociatedObject.ActualWidth); this.AssociatedObject.Children.Add(flake); } } private void AssociatedObject_SizeChanged(object sender, SizeChangedEventArgs e) { GenerateSnowFlakes(); _gameLoop.Start(); } private void gameLoop_Tick(object sender, EventArgs e) { foreach (SnowFlake flake in this.AssociatedObject.Children) { flake.Update(); } } } }

You can download the sourcecode from here.


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