Dart Function not inputting Variables - flutter

Question

I'm creating a Dart Function to use repeatedly across my app. its 2 buttons linked to a counter locally (localCounter, it's between the 2 buttons) as well as linked to a counter that catches all the button presses across the app (GlobalCuonter) when I input the the integers directly into the code, it works fine but when I use the it as a function, and make it so i can input the variables, it doesn't seem to work but i'm also not getting any errors in the code.
import 'package:flutter/material.dart';
void main() {
runApp(
const MyApp(),
);
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: Scaffold(
backgroundColor: Colors.black,
body: SafeArea(
child: MainPage(),
),
),
);
}
}
class MainPage extends StatefulWidget {
const MainPage({Key? key}) : super(key: key);
#override
State<MainPage> createState() => _MainPageState();
}
class _MainPageState extends State<MainPage> {
int TP1LeftCounter = 0; //localCounter
int movpLeftCounter = 0; //globalCounter
Row TpScores(int localCounter, int globalCounter) { //Dart Function I'm trying to create
return Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
ClipRRect(
borderRadius: BorderRadius.circular(5.0),
child: InkWell(
onTap: () {
setState(() {
if (localCounter > 0) localCounter--;
if (globalCounter > 0) globalCounter--;
});
},
child: Container(
child: Icon(Icons.remove, color: Colors.white),
width: 25.0,
height: 35.0,
color: Colors.blueGrey[900],
),
),
),
Container(
child: Text(
'$localCounter',
style: TextStyle(
fontFamily: 'SourceSansPro',
fontSize: 40.0,
color: Colors.white,
fontWeight: FontWeight.bold,
),
),
),
ClipRRect(
borderRadius: BorderRadius.circular(5.0),
child: InkWell(
onTap: () {
setState(() {
if (localCounter < 12) localCounter++;
if (globalCounter < 12) globalCounter++;
});
},
child: Container(
child: Icon(Icons.add, color: Colors.white),
width: 25.0,
height: 35.0,
color: Colors.blueGrey[900],
),
),
),
],
);
}
A
nd then in my build i put:
Expanded(
child: Container(
height: 50.0,
child: TpScores(TP1LeftCounter, movpLeftCounter),
),
),
the counters don't tick up or down but the buttons are working.
am I missing something? cheers

Answer 1

It's because the value is copied, you're not incrementing TP1LeftCounter and movpLeftCounter but localCounter and globalCounter
You should increment TP1LeftCounter, movpLeftCounter in the setState method.
Example
void main() {
var v1 = 0;
void incr(int value) {
value++;
print('value is $value');
print('v1 is $v1');
}
incr(v1);
}
Will output
value is 1
v1 is 0