DavideZordan.net

I’ve received several requests about the modalities of enabling multi-touch on a UI element using the Behavior available on my CodePlex project.

The traditional syntax using XAML is here:

<Image Source="Images/Desert.jpg" x:Name="image1">
    <interactivity:Interaction.Behaviors>
        <Silverlight4:MultiTouchBehavior 
            IsInertiaEnabled="True"
            IsTranslateXEnabled="True" 
            IsTranslateYEnabled="True"
            IsRotateEnabled="True" 
            IsScaleEnabled="True"
            MinimumScale="10" MaximumScale="100"
            AreFingersVisible="True"/>
    </interactivity:Interaction.Behaviors>
</Image>

What about if you want to achieve the same result using C#? Just obtain a collection of behaviors for your element and then add/remove the MultiTouchBehavior using the following syntax:

private void btnAttach_Click(object sender, RoutedEventArgs e)
{
    var behaviors = 
        System.Windows.Interactivity
        .Interaction.GetBehaviors(image1);
    behaviors.Clear();
    var mtb = new MultiTouchBehavior
    {
        IsRotateEnabled = true,
        IsScaleEnabled = true,
        IsTranslateXEnabled = true,
        IsInertiaEnabled = true,
        AreFingersVisible = true,
        MinimumScale = 20,
        MaximumScale = 200
    };
    behaviors.Add(mtb);
    mtb.Move(new Point(200, 150), 45, 100);
}

private void btnDetach_Click(object sender, RoutedEventArgs e)
{
    var behaviors = 
        System.Windows.Interactivity
        .Interaction.GetBehaviors(image1);
    if (behaviors.Count > 0)
    {
        behaviors.Clear();
    }
}

As usually the source code is available for download on the Multi-Touch CodePlex project (check out the SilverlightWP7MultiTouch Solution).

Oh, did I already say that it also works on Windows Phone 7?

Happy Silverlighting!