Can't Update a String Variable After initializing it in Flutter - string

Question

I want to Update the new value of the 'holecode' variable in 'inputform.dart' then get this new value to the 'otpscreen.dart'
The Problem that in each time I try to get the value of the 'holecode' string variable I get the 'default' value which I initialize it.I tried to make the 'holecode' variable as late String holecode; but it return Null in the second Screen in each time I try to get it's value.
inputform.dart:
import 'package:flutter/material.dart';
class Inputform extends StatefulWidget {
List<String> code = ["","","","","",""];
String holeCode = "default";
#override
State<Inputform> createState() => InputformState();
}
class InputformState extends State<Inputform> {
#override
Widget build(BuildContext context) {
return TextFormField(
onChanged: (value) {
setState(() {
widget.code[0] = value;
widget.holeCode = widget.code[0] + 222205;
});
if (value.length == 1) {
FocusScope.of(context).nextFocus();
}
}
),
},
otp.dart:
import 'package:flutter/material.dart';
class OtpVerification extends StatefulWidget {
#override
State<StatefulWidget> createState() => Otp();
}
class Otp extends State<OtpVerification> {
final Inputform ani= new Inputform ();
#override
Widget build(BuildContext context) {
return Scaffold(
child:
FlatButton(
onPressed: () {
// trying to print the new value in this screen but it
//return the default value 'default'
print(ani.holeCode);
),
);
}

Answer 1

Try this:
Have your InputForm like so:
class Inputform extends StatefulWidget {
final ValueChanged<String> onHoleCodeChanged;
const Inputform({
Key? key,
required this.onHoleCodeChanged,
}) : super(key: key);
#override
State<Inputform> createState() => InputformState();
}
class InputformState extends State<Inputform> {
List<String> code = ["", "", "", "", "", ""];
String holeCode = "default";
#override
Widget build(BuildContext context) {
return TextFormField(onChanged: (value) {
setState(() {
code[0] = value;
holeCode = code[0] + "222205";
widget.onHoleCodeChanged(holeCode);
});
if (value.length == 1) {
FocusScope.of(context).nextFocus();
}
});
}
}
And have your OTP class like so:
class OtpVerification extends StatefulWidget {
#override
State<StatefulWidget> createState() => Otp();
}
class Otp extends State<OtpVerification> {
late Inputform ani;
#override
void initState() {
ani = Inputform(
onHoleCodeChanged: (v) {
setState(() {
aniHoleCode = v;
});
},
);
super.initState();
}
String aniHoleCode = "";
#override
Widget build(BuildContext context) {
return Scaffold(
body: FlatButton(
child: Text("Button"),
onPressed: () {print(aniHoleCode);},
),
);
}
}