stuff BitBlt memory leak

namespace REghZy.FrameControl {
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window {
        [DllImport("gdi32.dll")]
        public static extern IntPtr CreateDC(
            [MarshalAs(UnmanagedType.LPStr)] string lpszDriver,
            [MarshalAs(UnmanagedType.LPStr)] string lpszDevice,
            [MarshalAs(UnmanagedType.LPStr)] string lpszOutput,
            IntPtr pdm);
        [DllImport("gdi32.dll")]
        public static extern bool DeleteObject(IntPtr hObject);
        [DllImport("gdi32.dll")]
        public static extern bool SelectObject(IntPtr hObject);
        [DllImport("user32.dll")]
        static extern bool ReleaseDC(IntPtr hWnd, IntPtr hDc);

        [DllImport("gdi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        public static extern int BitBlt(
            IntPtr hDC,
            int x,
            int y,
            int nWidth,
            int nHeight,
            IntPtr hSrcDC,
            int xSrc,
            int ySrc,
            int dwRop);

        private long lastFrameTime;

        public static IntPtr DESKTOP = CreateDC("DISPLAY", null, null, IntPtr.Zero);
        public readonly Bitmap result;
        public readonly IntPtr ptr;

        public Graphics g;

        private long nextRunTicks;

        public MainWindow() {
            InitializeComponent();

            this.result = new Bitmap(1920, 1080, PixelFormat.Format24bppRgb);

            Task.Run(async () => {
                while (true) {
                    Timer_Tick();
                    // DateTime time = DateTime.Now;
                    // if (time.Ticks > this.nextRunTicks) {
                    //     this.nextRunTicks = time.Ticks + TimeSpan.FromMilliseconds(1d).Ticks;
                    //     Timer_Tick();
                    // }
                    // else {
                    //     await Task.Delay(1);
                    // }
                }
            });
        }

        public static void RunTaskOnMainThread(Action action) {
            TaskCompletionSource<bool> tcs = new TaskCompletionSource<bool>();
            Application.Current.Dispatcher.Invoke(() => {
                try {
                    action();
                }
                finally {
                    tcs.TrySetResult(true);
                }
            });

            tcs.Task.Wait();
        }


        private void Timer_Tick() {
            long start = DateTime.Now.Ticks;
            Capture(this.result, () => {
                try {
                    BitmapSource source = Imaging.CreateBitmapSourceFromHBitmap(this.result.GetHbitmap(), IntPtr.Zero, Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());
                    source.Freeze();
                    RunTaskOnMainThread(() => {
                        this.Display.Text = $"Difference: {new DateTime(start - this.lastFrameTime).Millisecond} millis";
                        this.Frame.Source = source;
                    });
                }
                catch (Exception e) {
                }
                finally {
                    // DeleteObject(this.result.GetHbitmap());
                }
            });

            this.lastFrameTime = start;
        }

        public static void Capture(Bitmap bitmap, Action callback) {
            Rectangle bounds = new Rectangle(0, 0, 1920, 1080);
            using (Graphics g = Graphics.FromImage(bitmap)) {
                int width = bounds.Size.Width;
                int height = bounds.Size.Height;
                try {
                    if (BitBlt(g.GetHdc(), 0, 0, width, height, DESKTOP, bounds.Left, bounds.Top, 13369376) == 0) // 13369376 == SourceCopy
                        throw new Win32Exception();
                    callback();
                }
                finally {
                    g.ReleaseHdc();
                    // DeleteObject(hdc);
                }
                // g.CopyFromScreen(new Point(bounds.Left, bounds.Top), Point.Empty, bounds.Size);
            }

            // Rectangle bounds = new Rectangle(0, 0, 1920, 1080);
            // using (Bitmap result = new Bitmap(bounds.Width, bounds.Height, PixelFormat.Format24bppRgb)) {
            //     using (Graphics g = Graphics.FromImage(result)) {
            //         g.CopyFromScreen(new Point(bounds.Left, bounds.Top), Point.Empty, bounds.Size);
            //         BitmapData data = result.LockBits(bounds, ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
            //         try {
            //             unsafe {
            //                 return Image.WrapMemory<Rgb24>((void*) data.Scan0, bounds.Width, bounds.Height).CloneAs<Rgb24>();
            //             }
            //         }
            //         finally {
            //             result.UnlockBits(data);
            //         }
            //     }
            // }
        }

        [StructLayout(LayoutKind.Sequential)]
        private struct Rect {
            public int Left;
            public int Top;
            public int Right;
            public int Bottom;
        }
    }
}