将整个silverlight控件导出到图像

Question

我正在尝试将silverlight控件保存到图像中，但是当控件内部有scrollviewer时会遇到麻烦。

所以我得到了我在屏幕上看到的确切图片（裁剪并使用滚动条）。 如何获得正确的结果，如下图所示？

这是xaml：

<Grid x:Name="LayoutRoot" Background="White">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>
    <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
        <Button Content="save" Click="ButtonBase_OnClick" Width="100" Margin="5"/>
    </StackPanel>
    <ScrollViewer Grid.Row="1">
        <Border Background="Gray" Width="100" Height="100" BorderBrush="Black" BorderThickness="5"/>
    </ScrollViewer>
</Grid>

按钮处理程序：

private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
    {
        ScaleTransform scaleTrans = new ScaleTransform();
        double scale = 1;
        scaleTrans.CenterX = 0;
        scaleTrans.CenterY = 0;
        scaleTrans.ScaleX = scale;
        scaleTrans.ScaleY = scale;
        var bitmap = new WriteableBitmap(LayoutRoot, scaleTrans);
        var i = Telerik.Windows.Media.Imaging.BitmapFrame.Create(bitmap);
        var dialog = new SaveFileDialog
        {
            Filter = "Png (*.png)|*.png",
            DefaultExt = "png",
        };

        if (dialog.ShowDialog() == true)
        {
            using (Stream stream = dialog.OpenFile())
            {
                var encoder = new Telerik.Windows.Media.Imaging.PngBitmapEncoder();
                encoder.Frames.Add(i);
                encoder.Save(stream);
            }
        }
    }