/// <summary>
        /// Refresh the contents of the directory.
        /// </summary>
        public void Refresh(StandardIcons?iconSize = default)
        {
            if (iconSize is null)
            {
                iconSize = _IconSize;
            }

            _Children.Clear();
            _Folders.Clear();

            FileObject      fobj;
            DirectoryObject dobj;
            IShellItem      shitem = null;
            IShellFolder    shfld;
            IEnumIDList     enumer;

            MemPtr mm;
            var    mm2 = new MemPtr();

            string fp;

            string pname = ParsingName;

            if (pname is object && pname.LastIndexOf(@"\") == pname.Length - 1)
            {
                pname = pname.Substring(0, pname.Length - 1);
            }

            var argriid = Guid.Parse(ShellIIDGuid.IShellItem);
            var res     = NativeShell.SHCreateItemFromParsingName(ParsingName, IntPtr.Zero, ref argriid, ref shitem);

            _IconSize = (StandardIcons)iconSize;

            int?argiIndex = null;

            _Icon      = Resources.GetFileIcon(ParsingName, FileObject.StandardToSystem(_IconSize), iIndex: ref argiIndex);
            _IconImage = Resources.GetFileIconWPF(ParsingName, FileObject.StandardToSystem(_IconSize));

            if (res == HResult.Ok)
            {
                var argbhid  = Guid.Parse(ShellBHIDGuid.ShellFolderObject);
                var argriid1 = Guid.Parse(ShellIIDGuid.IShellFolder2);

                shitem.BindToHandler(IntPtr.Zero, ref argbhid, ref argriid1, out shfld);
                _SysInterface = shfld;

                shfld.EnumObjects(IntPtr.Zero, ShellFolderEnumerationOptions.Folders | ShellFolderEnumerationOptions.IncludeHidden | ShellFolderEnumerationOptions.NonFolders | ShellFolderEnumerationOptions.InitializeOnFirstNext, out enumer);

                if (enumer != null)
                {
                    var    glist = new List <string>();
                    uint   cf;
                    var    x = IntPtr.Zero;
                    string pout;

                    // mm.AllocCoTaskMem((MAX_PATH * 2) + 8)

                    mm2.Alloc(NativeShell.MAX_PATH * 2 + 8);

                    do
                    {
                        cf = 0U;
                        mm2.ZeroMemory(0L, NativeShell.MAX_PATH * 2 + 8);
                        res = enumer.Next(1U, out x, out cf);
                        mm  = x;

                        if (cf == 0L)
                        {
                            break;
                        }

                        if (res != HResult.Ok)
                        {
                            break;
                        }

                        mm2.IntAt(0L) = 2;

                        // shfld.GetAttributesOf(1, mm, attr)
                        shfld.GetDisplayNameOf(mm, (uint)ShellItemDesignNameOptions.ParentRelativeParsing, mm2.handle);
                        MemPtr inv;

                        if (IntPtr.Size == 4)
                        {
                            inv = (IntPtr)mm2.IntAt(1L);
                        }
                        else
                        {
                            inv = (IntPtr)mm2.LongAt(1L);
                        }

                        if (inv.Handle != IntPtr.Zero)
                        {
                            if (inv.CharAt(0L) != '\0')
                            {
                                fp = (string)inv;
                                var lpInfo = new SHFILEINFO();

                                // Dim sgfin As ShellFileGetAttributesOptions = 0,
                                // sgfout As ShellFileGetAttributesOptions = 0

                                int iFlags = User32.SHGFI_PIDL | User32.SHGFI_ATTRIBUTES;
                                lpInfo.dwAttributes = 0;
                                x = User32.SHGetItemInfo(mm.Handle, 0, ref lpInfo, Marshal.SizeOf(lpInfo), iFlags);
                                if (ParsingName is object)
                                {
                                    if (pname.LastIndexOf(@"\") == pname.Length - 1)
                                    {
                                        pname = pname.Substring(0, pname.Length - 1);
                                    }
                                    pout = $@"{pname}\{fp}";
                                }
                                else
                                {
                                    pout = fp;
                                }

                                if (lpInfo.dwAttributes == 0)
                                {
                                    lpInfo.dwAttributes = (int)FileTools.GetFileAttributes(pout);
                                }

                                FileAttributes drat = (FileAttributes)(int)(lpInfo.dwAttributes);
                                if ((lpInfo.dwAttributes & (int)FileAttributes.Directory) == (int)FileAttributes.Directory && !File.Exists(pout))
                                {
                                    dobj          = new DirectoryObject(pout, _IsSpecial, false);
                                    dobj.Parent   = this;
                                    dobj.IconSize = _IconSize;
                                    _Children.Add(dobj);
                                    _Folders.Add(dobj);
                                }
                                else
                                {
                                    fobj          = new FileObject(pout, _IsSpecial, true, _IconSize);
                                    fobj.Parent   = this;
                                    fobj.IconSize = _IconSize;
                                    _Children.Add(fobj);
                                }
                            }

                            inv.CoTaskMemFree();
                        }

                        mm.CoTaskMemFree();
                    }while (res == HResult.Ok);
                    mm2.Free();
                }
            }

            OnPropertyChanged(nameof(Folders));
            OnPropertyChanged(nameof(Icon));
            OnPropertyChanged(nameof(IconImage));
            OnPropertyChanged(nameof(IconSize));
            OnPropertyChanged(nameof(ParsingName));
            OnPropertyChanged(nameof(DisplayName));
        }