XAML Storyboard for Background ImageBrush - xaml

Question

I have the following XAML Grid:
<Grid Style="{StaticResource LayoutRootStyle}" x:Name="mainGrid">
<Grid.Resources>
<Storyboard x:Name="FadeOut">
<DoubleAnimation Duration="3" To="0.0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="gridBackgroundImageBrush" d:IsOptimized="True"/>
</Storyboard>
<Storyboard x:Name="FadeIn">
<DoubleAnimation Duration="3" To="0.35" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="gridBackgroundImageBrush" d:IsOptimized="True"/>
</Storyboard>
</Grid.Resources>
<Grid.Background>
<ImageBrush x:Name="gridBackgroundImageBrush" ImageSource="{Binding BackgroundImage}" Opacity="0.35">
</ImageBrush>
</Grid.Background>
I want to programmatically start the "FadeOut" animation and change the Image from ImageBrush, then start the "FadeIn" animation, like this:
private void t_Tick(object sender, object e)
{
try
{
FadeOut.Begin();
this.DefaultViewModel["BackgroundImage"] = BackgroundImage;
FadeIn.Begin();
}
catch { }
}
However the image is changing without any animation. I guess the problem is about how I'm accessing the "Opacity" property of the ImageBrush. I tried the following syntax for the
TargetProperty attribute:
(Control.Background).(ImageBrush.Opacity)
as msdn shows here: http://msdn.microsoft.com/en-us/library/windows/apps/windows.ui.xaml.media.animation.storyboard.settargetproperty.aspx but it doesn't seem to work. Can someone help me with this problem?

Answer 1

The solution was to create an image control rather than drawing the image with ImageBrush and then defining visual states for fading:
<Grid Style="{StaticResource LayoutRootStyle}" x:Name="mainGrid">
<Image Grid.RowSpan="2" x:Name="gridBackgroundImageBrush" Source="{Binding BackgroundImage}" />
</Grid>
<VisualStateGroup x:Name="FadeStates">
<VisualState x:Name="FadeOutState">
<Storyboard>
<DoubleAnimation Duration="{Binding fadeDuration}" From="0.5" To="0.0" x:Name="fadeOutAnimation"
Storyboard.TargetProperty="Opacity"
Storyboard.TargetName="gridBackgroundImageBrush" />
</Storyboard>
</VisualState>
<VisualState x:Name="FadeInState">
<Storyboard>
<DoubleAnimation Duration="{Binding fadeDuration}" From="0.0" To="0.5" x:Name="fadeInAnimation"
Storyboard.TargetProperty="Opacity"
Storyboard.TargetName="gridBackgroundImageBrush" />
</Storyboard>
</VisualState>
</VisualStateGroup>