❔ problem changing the opacity of desktop icons via windows api

  private const int GWL_EXSTYLE = -20;
        const int WS_EX_LAYERED = 0x00080000;    // Creates a layered window. 
        const int WS_EX_TRANSPARENT = 0x00000020;    // Not painted until after siblings beneath the window 
        const int WS_EX_TOOLWINDOW = 0x00000080;    // Creates a floating toolbar window, does not appear in the taskba
        private const int LWA_ALPHA = 0x2;


        public static int CurrentAlpha = GetDesktopIconOpacity();
        public static void SetDesktopIconsOpacity(int Alpha)
        {
            IntPtr hWnd = GetDesktopHwnd();

            IntPtr exStyle = NativeMethods.GetWindowLong(hWnd, GWL_EXSTYLE);

            // 
            NativeMethods.SetWindowLong(hWnd, GWL_EXSTYLE, (IntPtr)(exStyle.ToInt64() | WS_EX_LAYERED | WS_EX_TOOLWINDOW));


            int CoreAlpha = (int)(255 * (double)Alpha / 100);

            if (Alpha != 100 & Alpha != 0)
            {
                CoreAlpha += 1;
            }

            NativeMethods.SetLayeredWindowAttributes(hWnd, 0, (byte)CoreAlpha, LWA_ALPHA);
            //NativeMethods.SendMessage(hWnd, (0x1000 + 38), IntPtr.Zero, (IntPtr)ColorTranslator.ToWin32(Color.Transparent));

            //NativeMethods.UpdateWindow(hWnd);

            CurrentAlpha = Alpha;
        }

  private const int GWL_EXSTYLE = -20;
        const int WS_EX_LAYERED = 0x00080000;    // Creates a layered window. 
        const int WS_EX_TRANSPARENT = 0x00000020;    // Not painted until after siblings beneath the window 
        const int WS_EX_TOOLWINDOW = 0x00000080;    // Creates a floating toolbar window, does not appear in the taskba
        private const int LWA_ALPHA = 0x2;


        public static int CurrentAlpha = GetDesktopIconOpacity();
        public static void SetDesktopIconsOpacity(int Alpha)
        {
            IntPtr hWnd = GetDesktopHwnd();

            IntPtr exStyle = NativeMethods.GetWindowLong(hWnd, GWL_EXSTYLE);

            // 
            NativeMethods.SetWindowLong(hWnd, GWL_EXSTYLE, (IntPtr)(exStyle.ToInt64() | WS_EX_LAYERED | WS_EX_TOOLWINDOW));


            int CoreAlpha = (int)(255 * (double)Alpha / 100);

            if (Alpha != 100 & Alpha != 0)
            {
                CoreAlpha += 1;
            }

            NativeMethods.SetLayeredWindowAttributes(hWnd, 0, (byte)CoreAlpha, LWA_ALPHA);
            //NativeMethods.SendMessage(hWnd, (0x1000 + 38), IntPtr.Zero, (IntPtr)ColorTranslator.ToWin32(Color.Transparent));

            //NativeMethods.UpdateWindow(hWnd);

            CurrentAlpha = Alpha;
        }

        public static int GetDesktopIconOpacity() => NativeMethods.GetLayeredWindowAttributes(GetDesktopHwnd(), out uint crKey, out byte bAlpha, out uint dwFlags) ? (100 * bAlpha) / 255 : 255;

        private static Process ExplorerProcess;
        private static IntPtr LastExplorerIconsHandle;
        private static IntPtr GetDesktopHwnd()
        {
            if (ExplorerProcess != null)
            {
                if (ExplorerProcess.HasExited)
                {
                    ExplorerProcess = null;

                    return GetDesktopHwnd();
                }
                else
                {
                    return LastExplorerIconsHandle;
                }
            }

            ExplorerProcess = Process.GetProcessesByName("explorer").FirstOrDefault();

            IntPtr hWnd = NativeMethods.FindWindow("Progman", "Program Manager");
            hWnd = NativeMethods.FindWindowEx(hWnd, IntPtr.Zero, "SHELLDLL_DefView", null);
            hWnd = NativeMethods.FindWindowEx(hWnd, IntPtr.Zero, "SysListView32", "FolderView");

            if (hWnd == IntPtr.Zero)
            {
                IntPtr hDesktop = NativeMethods.GetDesktopWindow();

                foreach (var handle in GetChildWindows(hDesktop))
                {
                    hWnd = NativeMethods.FindWindowEx(handle, IntPtr.Zero, "SHELLDLL_DefView", null);

                    if (hWnd == IntPtr.Zero)
                    {
                        continue;
                    }

                    hWnd = NativeMethods.FindWindowEx(hWnd, IntPtr.Zero, "SysListView32", "FolderView");

                    if (hWnd != IntPtr.Zero)
                    {
                        break;
                    }
                }
            }

            LastExplorerIconsHandle = hWnd;

            return hWnd;
        }

        public static int GetDesktopIconOpacity() => NativeMethods.GetLayeredWindowAttributes(GetDesktopHwnd(), out uint crKey, out byte bAlpha, out uint dwFlags) ? (100 * bAlpha) / 255 : 255;

        private static Process ExplorerProcess;
        private static IntPtr LastExplorerIconsHandle;
        private static IntPtr GetDesktopHwnd()
        {
            if (ExplorerProcess != null)
            {
                if (ExplorerProcess.HasExited)
                {
                    ExplorerProcess = null;

                    return GetDesktopHwnd();
                }
                else
                {
                    return LastExplorerIconsHandle;
                }
            }

            ExplorerProcess = Process.GetProcessesByName("explorer").FirstOrDefault();

            IntPtr hWnd = NativeMethods.FindWindow("Progman", "Program Manager");
            hWnd = NativeMethods.FindWindowEx(hWnd, IntPtr.Zero, "SHELLDLL_DefView", null);
            hWnd = NativeMethods.FindWindowEx(hWnd, IntPtr.Zero, "SysListView32", "FolderView");

            if (hWnd == IntPtr.Zero)
            {
                IntPtr hDesktop = NativeMethods.GetDesktopWindow();

                foreach (var handle in GetChildWindows(hDesktop))
                {
                    hWnd = NativeMethods.FindWindowEx(handle, IntPtr.Zero, "SHELLDLL_DefView", null);

                    if (hWnd == IntPtr.Zero)
                    {
                        continue;
                    }

                    hWnd = NativeMethods.FindWindowEx(hWnd, IntPtr.Zero, "SysListView32", "FolderView");

                    if (hWnd != IntPtr.Zero)
                    {
                        break;
                    }
                }
            }

            LastExplorerIconsHandle = hWnd;

            return hWnd;
        }

 [DllImport("user32.dll")]
        public static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);

        [DllImport("user32.Dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool EnumChildWindows(IntPtr parentHandle, Win32Callback callback, IntPtr lParam);

        public delegate bool Win32Callback(IntPtr hwnd, IntPtr lParam);

        List<IntPtr> GetRootWindowsOfProcess(int pid)
        {
            List<IntPtr> rootWindows = GetChildWindows(IntPtr.Zero);
            List<IntPtr> dsProcRootWindows = new List<IntPtr>();
            foreach (IntPtr hWnd in rootWindows)
            {
                uint lpdwProcessId;
                GetWindowThreadProcessId(hWnd, out lpdwProcessId);
                if (lpdwProcessId == pid)
                    dsProcRootWindows.Add(hWnd);
            }
            return dsProcRootWindows;
        }

        public static List<IntPtr> GetChildWindows(IntPtr parent)
        {
            List<IntPtr> result = new List<IntPtr>();
            GCHandle listHandle = GCHandle.Alloc(result);
            try
            {
                Win32Callback childProc = new Win32Callback(EnumWindow);

                EnumChildWindows(parent, childProc, GCHandle.ToIntPtr(listHandle));
            }
            finally
            {
                if (listHandle.IsAllocated)
                    listHandle.Free();
            }
            return result;
        }

        private static bool EnumWindow(IntPtr handle, IntPtr pointer)
        {
            GCHandle gch = GCHandle.FromIntPtr(pointer);
            List<IntPtr> list = gch.Target as List<IntPtr>;
            if (list == null)
            {
                throw new InvalidCastException("GCHandle Target could not be cast as List<IntPtr>");
            }
            list.Add(handle);

            return true;
        }

 [DllImport("user32.dll")]
        public static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);

        [DllImport("user32.Dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        public static extern bool EnumChildWindows(IntPtr parentHandle, Win32Callback callback, IntPtr lParam);

        public delegate bool Win32Callback(IntPtr hwnd, IntPtr lParam);

        List<IntPtr> GetRootWindowsOfProcess(int pid)
        {
            List<IntPtr> rootWindows = GetChildWindows(IntPtr.Zero);
            List<IntPtr> dsProcRootWindows = new List<IntPtr>();
            foreach (IntPtr hWnd in rootWindows)
            {
                uint lpdwProcessId;
                GetWindowThreadProcessId(hWnd, out lpdwProcessId);
                if (lpdwProcessId == pid)
                    dsProcRootWindows.Add(hWnd);
            }
            return dsProcRootWindows;
        }

        public static List<IntPtr> GetChildWindows(IntPtr parent)
        {
            List<IntPtr> result = new List<IntPtr>();
            GCHandle listHandle = GCHandle.Alloc(result);
            try
            {
                Win32Callback childProc = new Win32Callback(EnumWindow);

                EnumChildWindows(parent, childProc, GCHandle.ToIntPtr(listHandle));
            }
            finally
            {
                if (listHandle.IsAllocated)
                    listHandle.Free();
            }
            return result;
        }

        private static bool EnumWindow(IntPtr handle, IntPtr pointer)
        {
            GCHandle gch = GCHandle.FromIntPtr(pointer);
            List<IntPtr> list = gch.Target as List<IntPtr>;
            if (list == null)
            {
                throw new InvalidCastException("GCHandle Target could not be cast as List<IntPtr>");
            }
            list.Add(handle);

            return true;
        }