public Size GetDeviceResolution()

        {

            Size resolution = Size.Empty;

            var rawPixelsPerViewPixel = DisplayInformation.GetForCurrentView().RawPixelsPerViewPixel;

            foreach (var item in PointerDevice.GetPointerDevices())

            {

                resolution.Width = item.ScreenRect.Width * rawPixelsPerViewPixel;

                resolution.Height = item.ScreenRect.Height * rawPixelsPerViewPixel;

                break;

            }

            return resolution;

        }