public void PrintImage(Bitmap bitmap)
        {
            if (websocket != null)
            {
                PrintImageRequestMessage message = new PrintImageRequestMessage();
                PrintImage pi = new PrintImage();

                MemoryStream ms = new MemoryStream();
                bitmap.Save(ms, ImageFormat.Png);
                byte[] imgBytes    = ms.ToArray();
                string base64Image = Convert.ToBase64String(imgBytes);

                pi.Bitmap       = base64Image; // serialize image to string..
                message.payload = pi;
                websocket.Send(JsonUtils.serialize(message));
            }
        }
        public void PrintImage(Bitmap bitmap)
        {
            if (websocket != null)
            {
                PrintImageRequestMessage message = new PrintImageRequestMessage();
                PrintImage pi = new PrintImage();

                MemoryStream ms = new MemoryStream();
                bitmap.Save(ms, ImageFormat.Png);
                byte[] imgBytes = ms.ToArray();
                string base64Image = Convert.ToBase64String(imgBytes);

                pi.Bitmap = base64Image; // serialize image to string..
                message.payload = pi;
                websocket.Send(JsonUtils.serialize(message));
            }
        }