listDirectory static method
列出目录内容
Lists directory contents
Implementation
static FileResult<List<FileSystemEntity>> listDirectory(String path,
    {bool recursive = false}) {
  try {
    final directory = Directory(path);
    if (!directory.existsSync()) {
      return const FileResult.failure('Directory does not exist');
    }
    final entities = directory.listSync(recursive: recursive);
    return FileResult.success(entities);
  } catch (e, stack) {
    loge('Failed to list directory $path: $e\n$stack');
    return FileResult.failure(e.toString());
  }
}