silverlight 动画有关问题

silverlight 动画问题
用silverlight3.0做WINCE应用程序
在blend里做好了动画,但是程序控制播放动画时失败
调用storyboard.Begin();后返回值为:XR_E_STORYBOARD_BEGIN_INVALID_PROPERTY:
Silverlight for Windows Embedded cannot begin this storyboard. The property to be animated is invalid.

VC调用代码:
C/C++ code

   IXRStoryboardPtr sbShowWnd;
   if (FAILED(root->FindName(TEXT("sbShowWnd"), &sbShowWnd)))
    return -1;
   sbShowWnd->Begin();  //执行到这步了,但是返回值是XR_E_STORYBOARD_BEGIN_INVALID_PROPERTY


Xaml里代码:
XML code

<UserControl
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    x:Class="SESample.Page"
    Width="1024" Height="600" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d">
    <UserControl.Resources>
        <Storyboard x:Name="sbShowWnd" AutoReverse="False">
            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="imgBg2" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[0].(ScaleTransform.ScaleX)">
                <SplineDoubleKeyFrame KeyTime="00:00:00" Value="0.233"/>
                <SplineDoubleKeyFrame KeyTime="00:00:00.1000000" Value="0.325"/>
                <SplineDoubleKeyFrame KeyTime="00:00:00.2000000" Value="0.475"/>
                <SplineDoubleKeyFrame KeyTime="00:00:00.3000000" Value="0.686"/>
                <SplineDoubleKeyFrame KeyTime="00:00:00.5000000" Value="1.001"/>
            </DoubleAnimationUsingKeyFrames>
            <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="imgBg2" Storyboard.TargetProperty="(UIElement.RenderTransform).(TransformGroup.Children)[0].(ScaleTransform.ScaleY)">
                <SplineDoubleKeyFrame KeyTime="00:00:00" Value="0.233"/>
                <SplineDoubleKeyFrame KeyTime="00:00:00.1000000" Value="0.37"/>
                <SplineDoubleKeyFrame KeyTime="00:00:00.2000000" Value="0.527"/>
                <SplineDoubleKeyFrame KeyTime="00:00:00.3000000" Value="0.67"/>
                <SplineDoubleKeyFrame KeyTime="00:00:00.5000000" Value="0.978"/>
            </DoubleAnimationUsingKeyFrames>        
        </Storyboard>
    </UserControl.Resources>

    <Grid x:Name="LayoutRoot" Background="White">
        <Canvas x:Name="cvsMain">
            <Image Height="600" Width="1024" Source="bg.png" x:Name="imgBg" Canvas.Left="0" Canvas.Top="0" Stretch="UniformToFill"/>
            <Image Height="80" Width="246" Canvas.Left="397.365" Canvas.Top="408.5" Source="closeNormal.png" x:Name="imgClose"/>
            <TextBlock Height="69.757" Width="429.168" Canvas.Left="285.496" Canvas.Top="88.757" TextWrapping="Wrap" x:Name="tbTextBlock"  FontFamily="Verdana" FontSize="48"><Run Text="Silverlight Demo!" FontFamily="Verdana" FontSize="48" Foreground="#FF010907"/></TextBlock>
        </Canvas>
        <Canvas x:Name="cvsShutDown" Visibility="Visible">
            <Image Height="600" Width="1024" Source="ShutDownBg.png" x:Name="imgBg2" Stretch="UniformToFill" RenderTransformOrigin="0.5,0.5">
                <Image.RenderTransform>
                    <TransformGroup>
                        <ScaleTransform/>
                        <SkewTransform/>
                        <RotateTransform/>
                        <TranslateTransform/>
                    </TransformGroup>
                </Image.RenderTransform>
            </Image>
            <Image Height="112" Width="347" Canvas.Left="513.019" Canvas.Top="394.378" x:Name="imgShutDown" Source="imgTrans.png"/>
            <Image Height="112" Width="345.5" Source="imgTrans.png" x:Name="imgCancel" Canvas.Left="163.519" Canvas.Top="394.378"/>
        </Canvas>
    </Grid>
</UserControl>