How do I add ListView elements using FloatingActionButton in flutter?

Question

I'm currently learning flutter and I'm having trouble managing states. I used this flutter guide as a reference: https://docs.flutter.dev/ui/interactive#managing-state.

I'm getting an exception thrown: "Lookup failed: addTiles in @methods in _MyTileState in package:app_recipes/main.dart"

This is my code:

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: MyHome(),
    );
  }
}

class MyHome extends StatelessWidget {
  const MyHome({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        centerTitle: true,
        title: const Text('My App'),
      ),
      body: const MyTile(),
    );
  }
}

class MyTile extends StatefulWidget {
  const MyTile({super.key});

  @override
  State<MyTile> createState() => _MyTileState();
}

class _MyTileState extends State<MyTile> {
  int _tileCount = 5;

  void _addTiles()
  {
    setState(() {
      _tileCount += 1;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: ListView.builder(
        itemCount: _MyTileState()._tileCount,
        itemBuilder: (BuildContext context, index)
        {
          return  ListTile(
            leading: const Icon(Icons.list),
            trailing: Text(
              'Tile $_tileCount'
            ),
          );
        }
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _addTiles,
        child: const Icon(Icons.add),
      ),
    );
  }
}

Answer 1

You are accessing _tileCount via _MyTileState(), which is the Generic Object, not the current instance.

You could use this._tileCount or just outright _tileCount.