public IActionResult ListFiles()
        {
            var directory = @"C:\";
            var files     = System.IO.Directory.GetFiles(directory);
            var vm        = new ListFilesViewModel(directory, files);

            return(View(vm));
        }
        public IActionResult ListFilesService()
        {
            var directory = @"C:\";

            fileStorage.ChangeDirectory(directory);
            var files = fileStorage.GetCurrentFiles();
            var vm    = new ListFilesViewModel(directory, files);

            return(View(vm));
        }