xamarin cross platform drawing on image using skia -skiasharp

Hi,

I have created a xamarin cross-platform application to draw on an image and save the image with drawing using SkiaSharp.

Below code to draw an image in bitmap

        //code to draw an image
                    if (!string.IsNullOrEmpty(ImageData))
                    {
                        string strimg64 = ImageData.Split(',')[1];
                        if (!string.IsNullOrEmpty(strimg64))
                        {
                            byte[] imageBytes = Convert.FromBase64String(strimg64);
                            Stream fileStream = new MemoryStream(imageBytes);

                            // clear the canvas / fill with white
                            bitmapCanvas.DrawColor(SKColors.White);

                            // decode the bitmap from the stream
                            using (var stream = new SKManagedStream(fileStream))

                                bitmap = SKBitmap.Decode(stream);
                            using (var paint = new SKPaint())
                            {
                                bitmapCanvas.DrawBitmap(bitmap, SKRect.Create(width, height), paint);
                            }
                        }
                    }

And below code used to draw the image using finger move

            foreach (SKPath path in completedPaths)
                    {
                        bitmapCanvas.DrawPath(path, paint);
                    }

                    foreach (SKPath path in inProgressPaths.Values)
                    {
                        bitmapCanvas.DrawPath(path, paint);
                    }

I can draw paint on the image but the problem is cant save the image with the drawing done. Only the image is saving in the gallery. I have attached the git link with the source. Please help to solve this problem to save the image with drawing.