MemoApp with Flutter

main.dart

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

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Memo with Flutter',
      theme: ThemeData(
        primarySwatch: Colors.blueGrey,
      ),
      home: TextWidget(title: 'Memo with Flutter'),
    );
  }
}

class TextWidget extends StatefulWidget {
  TextWidget({Key key, this.title}) : super(key: key);
  final String title;

  @override
  _TextWidgetState createState() => _TextWidgetState();
}

class _TextWidgetState extends State<TextWidget>{
  @override
  Widget build(BuildContext context){
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),

      body: ListView(
        children: <Widget>[
          TextField(
            decoration: InputDecoration(
              border: OutlineInputBorder(),
              hintText: 'Write something',
            ),

            maxLines: null,
          ),
        ],
      )
    );
  }
}