Dart - CRUD file in path

20201004

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:path_provider/path_provider.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await getApplicationDocumentsDirectory().then((Directory dir) {
    File file = File('${dir.path}/text.txt');
    file.writeAsString('123');
    void read() async {
      String contents = await file.readAsString();
      print(contents);
    }

    read();
  });
}

 [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: FileSystemException: Cannot open file, path = '//test.txt' (OS Error: Read-only file system, errno = 30)

FileSystemException: Cannot open file OS Error: Is a directory

reading-writing-files