Blend Interaction Behaviour gives "points to immutable instance" error
- by kennethkryger
I have a UserControl that is a base class for other user controls, that are shown in "modal view".
I want to have all user controls fading in, when shown and fading out when closed. I also want a behavior, so that the user can move the controls around.My contructor looks like this:
var tg = new TransformGroup();
tg.Children.Add(new ScaleTransform());
RenderTransform = tg;
var behaviors = Interaction.GetBehaviors(this);
behaviors.Add(new TranslateZoomRotateBehavior());
Loaded += ModalDialogBase_Loaded;
And the ModalDialogBase_Loaded method looks like this:
private void ModalDialogBase_Loaded(object sender, RoutedEventArgs e)
{
var fadeInStoryboard = (Storyboard)TryFindResource("modalDialogFadeIn");
fadeInStoryboard.Begin(this);
}
When I press a Close-button on the control this method is called:
protected virtual void Close()
{
var fadeOutStoryboard = (Storyboard)TryFindResource("modalDialogFadeOut");
fadeOutStoryboard = fadeOutStoryboard.Clone();
fadeOutStoryboard.Completed += delegate
{
RaiseEvent(new RoutedEventArgs(ClosedEvent));
};
fadeOutStoryboard.Begin(this);
}
The storyboard for fading out look like this:
<Storyboard x:Key="modalDialogFadeOut">
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[0].(ScaleTransform.ScaleX)" Storyboard.TargetName="{x:Null}">
<EasingDoubleKeyFrame KeyTime="0" Value="1">
<EasingDoubleKeyFrame.EasingFunction>
<BackEase EasingMode="EaseIn" Amplitude="0.3" />
</EasingDoubleKeyFrame.EasingFunction>
</EasingDoubleKeyFrame>
<EasingDoubleKeyFrame KeyTime="0:0:0.4" Value="0">
<EasingDoubleKeyFrame.EasingFunction>
<BackEase EasingMode="EaseIn" Amplitude="0.3" />
</EasingDoubleKeyFrame.EasingFunction>
</EasingDoubleKeyFrame>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[0].(ScaleTransform.ScaleY)" Storyboard.TargetName="{x:Null}">
<EasingDoubleKeyFrame KeyTime="0" Value="1">
<EasingDoubleKeyFrame.EasingFunction>
<BackEase EasingMode="EaseIn" Amplitude="0.3" />
</EasingDoubleKeyFrame.EasingFunction>
</EasingDoubleKeyFrame>
<EasingDoubleKeyFrame KeyTime="0:0:0.4" Value="0">
<EasingDoubleKeyFrame.EasingFunction>
<BackEase EasingMode="EaseIn" Amplitude="0.3" />
</EasingDoubleKeyFrame.EasingFunction>
</EasingDoubleKeyFrame>
</DoubleAnimationUsingKeyFrames>
<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Opacity)" Storyboard.TargetName="{x:Null}">
<EasingDoubleKeyFrame KeyTime="0" Value="1" />
<EasingDoubleKeyFrame KeyTime="0:0:0.3" Value="0" />
<EasingDoubleKeyFrame KeyTime="0:0:0.4" Value="0" />
</DoubleAnimationUsingKeyFrames>
</Storyboard>
If the user control is show, and the user does NOT move it around on the screen, everything works fine. However, if the user DOES move the control around, I get the following error when the modalDialogFadeOut storyboard is started:
'Children' property value in the path '(0).(1)[0].(2)' points to immutable instance of 'System.Windows.Media.TransformCollection'.
How can fix this?
