Can't able to focus on newly added text field flutter - flutter

Question

import 'package:flutter/material.dart';
class Demo {
int no;
String value;
Demo({this.value, this.no});
}
class Control {
TextEditingController controller;
FocusNode node;
Control({this.controller, this.node});
}
class DemoPage extends StatefulWidget {
static const routeName = '/Demo';
DemoPage({Key key}) : super(key: key);
#override
_DemoPageState createState() => _DemoPageState();
}
class _DemoPageState extends State<DemoPage> {
List<Demo> txtfield;
List<Control> control;
#override
void initState() {
txtfield = [];
control = [];
// no = 0;
add();
super.initState();
}
int no;
void add() {
no = (no ?? 0) + 1;
setState(() {});
txtfield.add(Demo(no: no));
control.add(Control(
controller: TextEditingController(),
node: FocusNode(),
));
// no = no +1;
}
#override
Widget build(BuildContext context) {
// print(txtfield[0].no);
// FocusScope.of(context).requestFocus(control[control.length - 1].node);
return Scaffold(
appBar: AppBar(),
body: Center(
child: Card(
child: Container(
child: Column(
children: txtfield
.map((f) => TextField(
controller: control[f.no - 1].controller,
focusNode: control[f.no - 1].node,
autofocus: true,
))
.toList(),
),
width: 400,
padding: EdgeInsets.all(20),
),
),
),
floatingActionButton: FloatingActionButton(
child: Icon(Icons.add),
onPressed: () {
add();
print(no);
FocusScope.of(context).requestFocus(control[control.length - 1].node);
},
),
);
}
}
I used above code. but I can't able to focus on a newly added text field.
when I check for that newly added text field has focus, it shows true, but I can't able to write anything in that text field.
I don't know what is an error in that code.
I search for this solution for more than 4 days. but I can't able to find solution.

Answer 1

At the onPressed of your floatingActionButton change this line:
FocusScope.of(context).requestFocus(control[control.length - 1].node);
with this
control[control.length - 1].node.requestFocus();