wpf GeometryDrawing 繪制文字

<GeometryDrawing x:Key="GeometryDrawingText">
<GeometryDrawing.Geometry>
<RectangleGeometry Rect="0,0,5,3"></RectangleGeometry>
</GeometryDrawing.Geometry>
<GeometryDrawing.Brush>
<VisualBrush>
<VisualBrush.Visual>
<!--<StackPanel>-->
<TextBlock Text="12.36" FontSize="0.01" FontWeight="Light" Foreground="White"></TextBlock>
<!--</StackPanel>-->
</VisualBrush.Visual>
</VisualBrush>
</GeometryDrawing.Brush>
</GeometryDrawing>