21 Flutter: Updating data in TextField

main.dart
import 'package:flutter/material.dart';
void main(){
runApp(new MaterialApp(
home: new MyApp(),
));
}
class MyApp extends StatefulWidget {
_State createState() => new _State();
}
//State is information of the application that can change over time or when some actions are taken.
class _State extends State<MyApp>{
String _value = '';
void _onChanged(String value) {
setState(() => _value = 'Change: ${value}');
}
void _onSubmit(String value) {
setState(() => _value = 'Submit: ${value}');
}
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('Name here'),
),
//hit Ctrl+space in intellij to know what are the options you can use in flutter widgets
body: new Container(
padding: new EdgeInsets.all(32.0),
child: new Center(
child: new Column(
children: <Widget>[
new Text(_value),
new TextField(
decoration: new InputDecoration(
labelText: 'Hello',
hintText: 'Hint',
icon: new Icon(Icons.people)
),
autocorrect: true,
autofocus: true,
//displaying number keyboard
//keyboardType: TextInputType.number,
//displaying text keyboard
keyboardType: TextInputType.text,
onChanged: _onChanged,
onSubmitted: _onSubmit,
)
],
),
),
),
);
}
}