TextBlock Curve in Windows 8

I want to create a Curved TextBlock using XAML, for example:

I do it like this:

<TextBlock TextWrapping="Wrap" Text="TextBlock" FontSize="30" Height="46"
           Width="182" RenderTransformOrigin="0.5,0.5" HorizontalAlignment="Left"
           VerticalAlignment="Top" Canvas.ZIndex="-1" Foreground="White"
           Margin="486,125,0,0" UseLayoutRounding="False" d:LayoutRounding="Auto">
    <TextBlock.Projection>
        <PlaneProjection RotationZ="360" />
    </TextBlock.Projection>
    <TextBlock.RenderTransform>
        <CompositeTransform Rotation="-30"/>
    </TextBlock.RenderTransform>
</TextBlock>

But no success. Can you tell me the best way?