UIElement.ClipToBounds在WPF中,但不在Silverlight中.如何在Silverlight中进行模拟？

using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

namespace MySilverlightProject
{
    public class ClippingBorder : Border
    {
        protected override void OnRender(DrawingContext dc)
        {
            base.OnRender(dc);

            RectangleGeometry clipGeometry = new RectangleGeometry();
            clipGeometry.Rect = new Rect(0, 0, this.ActualWidth, this.ActualHeight);
            dc.PushClip(clipGeometry);

            // 在这里绘制你的内容
            // ...

            dc.Pop();
        }
    }
}

    <Grid>
        <!-- 在这里放置需要裁剪的内容 -->
        <TextBlock Text="Hello, Silverlight!" HorizontalAlignment="Center" VerticalAlignment="Center" />
    </Grid>
</local:ClippingBorder>