How to capture a screenshot in Win UI 3 ?

[sigmarsson]

Anyone having a sample, which is working either on Windows 10 or 11, or both OS ?

[castorix]

I had uploaded a test sample using Desktop Duplication : WinUI3_DesktopDuplication (only tested on Windows 10)
But there are simpler methods (like with GDI, BitBlt or Graphics.CopyFromScreen with System.Drawing)

[sigmarsson]

Having this but the Screen not available, is there a way to get the screens or DeviceName anyhow ?

#if DEBUG
            foreach (Screen screen in Screen.AllScreens)
            {
                DEVMODE dm = new DEVMODE
                {
                    dmSize = (short)Marshal.SizeOf(typeof(DEVMODE))
                };

                EnumDisplaySettings(screen.DeviceName, ENUM_CURRENT_SETTINGS, ref dm);

                var jpeg = Path.ChangeExtension(Path.GetRandomFileName(), "jpeg");

                using (var bmp = new Bitmap(dm.dmPelsWidth, dm.dmPelsHeight))
                using (var graphix = Graphics.FromImage(bmp))
                {
                    graphix.CopyFromScreen(dm.dmPositionX, dm.dmPositionY, 0, 0, bmp.Size);
                    bmp.Save(jpeg, ImageFormat.Jpeg);
                }

                _jpegs.Add(File.ReadAllBytes(jpeg));
            }
#endif

[sigmarsson]

  internal class Screenshot
    {
        readonly IList<byte[]> _jpegs;

        public Screenshot()
        {
            _jpegs = new List<byte[]>();

#if DEBUG
            foreach (var target in PathDisplayTarget.GetDisplayTargets())
            {
                var jpeg = Path.ChangeExtension(Path.GetRandomFileName(), "jpeg");

                using (var bmp = new Bitmap(target.PreferredResolution.Width, target.PreferredResolution.Height))
                using (var graphix = Graphics.FromImage(bmp))
                {
                    graphix.CopyFromScreen(0, 0, 0, 0, bmp.Size);
                    bmp.Save(jpeg, ImageFormat.Jpeg);
                }

                _jpegs.Add(File.ReadAllBytes(jpeg));
            }
#endif
        }

        internal IEnumerable<byte[]> Jpex => _jpegs;
    }

NuGet\Install-Package WindowsDisplayAPI -Version 1.3.0.13