BetterExplorer.FolderSizeWindow.RecurseDirectory C# (CSharp) Method

        private long RecurseDirectory(string directory, int level, out int files, out int folders)
        {
            IntPtr INVALID_HANDLE_VALUE = new IntPtr(-1);
            long size = 0;
            files = 0;
            folders = 0;
            WIN32_FIND_DATA findData;

            //IntPtr findHandle;

            // please note that the following line won't work if you try this on a network folder, like \\Machine\C$
            // simply remove the \\?\ part in this case or use \\?\UNC\ prefix
            IntPtr findHandle = FindFirstFile($@"\\?\{directory}\*", out findData);
            if (findHandle != INVALID_HANDLE_VALUE)
            {
                do
                {
                    if (bgw.CancellationPending)
                        break;

                    if ((findData.dwFileAttributes & System.IO.FileAttributes.Directory) != 0)
                    {
                        if (findData.cFileName != "." && findData.cFileName != "..")
                        {
                            folders++;

                            int subfiles, subfolders;
                            string subdirectory = directory + (directory.EndsWith(@"\") ? "" : @"\") +
                                    findData.cFileName;
                            if (level != 0)
                            { // allows -1 to do complete search.
                                size += RecurseDirectory(subdirectory, level - 1, out subfiles, out subfolders);

                                folders += subfolders;
                                files += subfiles;
                            }
                        }
                    }
                    else
                    {
                        // File
                        files++;

                        size += (long)findData.nFileSizeLow + (long)findData.nFileSizeHigh * 4294967296;
                    }
                }
                while (FindNextFile(findHandle, out findData));
                FindClose(findHandle);
            }

            return size;
        }