textfield

main.dart

import 'package:flutter/material.dart';

void main() => runApp(new MaterialApp(home: new MyHomePage()));

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key}) : super(key: key);

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {

  Widget createTextFieldListView(){
    return new ListView(
      shrinkWrap: true,
      reverse: true,
      children: <Widget>[
        new TextField(
          decoration: new InputDecoration(hintText: "Add text here"),
        ),
        new AspectRatio(
          aspectRatio: 1.0,
          child: new Container(
            color: Colors.green,
          ),
        ),
      ].toList(),
    );
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(title: new Text("textfield")),
      body: createTextFieldListView(),
    );
  }
}