silverlight animation question

Doe's anybody knows what wrong with markup below

<UserControl
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    x:Class="DoubleAnim.MainPage"
    Width="640" Height="480">
    <UserControl.Resources> 
        <Storyboard x:Name="Storyboard1">
            <DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(Canvas.Left)" Storyboard.TargetName="objectToAnimate">
                <EasingDoubleKeyFrame KeyTime="0" Value="0"/>
                <EasingDoubleKeyFrame KeyTime="0:0:1" Value="400"/>
            </DoubleAnimationUsingKeyFrames>                
        </Storyboard>
    </UserControl.Resources>

    <Grid x:Name="LayoutRoot" Background="White">
        <Rectangle x:Name="objectToAnimate" Fill="#FF0000F9" HorizontalAlignment="Left"  Canvas.Top="164"  Height="100" Stroke="Black" VerticalAlignment="Top" Width="192" RadiusY="8" RadiusX="8" >
        </Rectangle>
        <Button Content="Button"开发者_如何学Python Height="23" HorizontalAlignment="Left" Margin="132,180,0,0" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" />
    </Grid>
</UserControl>

Everything looks good but it not works:(( Doe's silverlight know how to animate canvas.top and canvas.left? Or maybe that I have missed something?

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You need a canvas object. Replace Grid with Canvas.

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The Canvas.Top and Canvas.Left attached properties are only used if the Rectangle (or UIElement) is hosted in a Canvas panel. The Grid uses different logic and attached properties to layout it's children.