The RenderTargetBitmap class worked with simple Canvas + InkManager (in Windows 8.1) to render ink strokes to an image. UWP introduced InkCanvas and a new Inking API. Howeve
Here is how I solved this issue with Win2D.
First of all, add Win2D.uwp
nuget package to your project.
Then use this code:
CanvasDevice device = CanvasDevice.GetSharedDevice();
CanvasRenderTarget renderTarget = new CanvasRenderTarget(device, (int)inkCanvas.ActualWidth, (int)inkCanvas.ActualHeight, 96);
using (var ds = renderTarget.CreateDrawingSession())
{
ds.Clear(Colors.White);
ds.DrawInk(inkCanvas.InkPresenter.StrokeContainer.GetStrokes());
}
using (var fileStream = await file.OpenAsync(FileAccessMode.ReadWrite))
await renderTarget.SaveAsync(fileStream, CanvasBitmapFileFormat.Jpeg, 1f);
Please try InkPresenter.StrokeContainer property http://blogs.windows.com/buildingapps/2015/09/08/going-beyond-keyboard-mouse-and-touch-with-natural-input-10-by-10/