获取父目录
Use the FileSystemEntity parent property to get the parent of a file, directory, or symlink. This property is inherited by File, Directory, and Link.
import 'dart:io';
import 'dart:async'; // Import not needed but added here to explicitly assign type for clarity below.
main() async {
// List the contents of the system temp directory.
Stream<FileSystemEntity> entityList =
Directory.systemTemp.list(recursive: true, followLinks: false);
await for (FileSystemEntity entity in entityList) print(entity.parent.path);
}