How to convert a ViewBox to an ImageSource?

Question

I'm using a Viewbox to create a set of icons that I will dynamically bind to a WPF view.

I'm binding to the resource name and using a Converter to convert the resource name to an ImageSource.

I know how to do it if the resource is a Path, but how to do it with a Viewbox?

This is how I convert the resource name, if the resource is a Path, to an ImageSource:

public class ResourceNameToImageSourceConverter : BaseValueConverter {
    protected override ImageSource Convert(string value, System.Globalization.CultureInfo culture) {
        var resource = new ResourceDictionary();
        resource.Source = new Uri("pack://application:,,,/MyAssembly;component/MyResourceFolder/ImageResources.xaml", UriKind.Absolute);
        var path = resource[value] as Path;
        if (path != null) {
            var geometry = path.Data;
            var geometryDrawing = new GeometryDrawing();
            geometryDrawing.Geometry = geometry;
            var drawingImage = new DrawingImage(geometryDrawing);

        geometryDrawing.Brush = path.Fill;
        geometryDrawing.Pen = new Pen();

        drawingImage.Freeze();
        return drawingImage;
    } else {
        return null;
    }
}


}

And this is what the Viewbox declaration looks like.

<Viewbox>
    <Viewbox>
      <Grid>
        <Path>
        ...
        </Path>
        <Path>
        ...
        </Path>
        <Path>
        ...
        </Path>
        <Rectangle>
        ...
        </Rectangle>
      </Grid>
    </Viewbox>
</Viewbox>

Answer 1

The Viewbox is a visual element, so you'd need to "render" it manually to a bitmap. This blog post shows how this is done, but the relevant code is:

private static BitmapSource CaptureScreen(Visual target, double dpiX, double dpiY) {
    if (target == null)
        return null;

    Rect bounds = VisualTreeHelper.GetDescendantBounds(target);
    RenderTargetBitmap rtb = new RenderTargetBitmap((int)(bounds.Width * dpiX / 96.0),
                                                (int)(bounds.Height * dpiY / 96.0),
                                                dpiX,
                                                dpiY,
                                                PixelFormats.Pbgra32);
    DrawingVisual dv = new DrawingVisual();
    using (DrawingContext ctx = dv.RenderOpen()) {
        VisualBrush vb = new VisualBrush(target);
        ctx.DrawRectangle(vb, null, new Rect(new Point(), bounds.Size));
    }

    rtb.Render(dv);
    return rtb;
}