Export all contents of grid to a image(not only visible area)

See more:

C#

XAML

WPF

I need to write a generic code snippet to export the contents of UserControl/Grid to a PNG image.
eg:

<Grid>
   <dockPanel>
     <Textblock>......<Textblock>
   <dockPanel>

<scrollViewer>
  <listView>
  .....
  </listview>
</scrollViewer>

<chart>....</chart>
......
<Grid>

I need to export above UI to PNG.

What I have tried:

public void ExportToPNG(FrameWorkElement element, Stream stream)
{
BitmapEncoder encoder = new PngBitmapEncoder();
	var bitmap = new RenderTargetBitmap(
				(int)element.RenderSize.Width,
				(int)element.RenderSize.Height,
				96,
				96,
				PixelFormats.Default);

Rect bounds = VisualTreeHelper.GetDescendantBounds(element);

			DrawingVisual drawingVisual = new DrawingVisual();
			using (DrawingContext context = drawingVisual.RenderOpen())
			{
				VisualBrush brush = new VisualBrush(element);
				Rect rect = new Rect(0, 0, bounds.Width, bounds.Height);

				context.DrawRectangle(Brushes.White, null, rect);
				context.DrawRectangle(brush, null, rect);
			}
bitmap.Render(drawingVisual);
encoder.Frames.Add(bitmap);
encoder.Save(stream);
}

The above code is working. But, it's just exporting the visible area(from the ScrollViewer). I need to export the whole content from the ScrollViewer.

Note: Some Views might not have ScrollViewer

Any advise or guidance would be greatly appreciated!

Thanks!