我试图理解状态是如何与Flutter一起工作的，我有一个子部件需要在父部件中更改一些内容。我可以使用打印检测子部件中按钮的按下。但是当我试图将此更改冒泡到父部件时，它没有捕捉到它。
我已经通过了一些教程，我不是100%肯定我了解状态如何工作或应该工作，我想我在这里错过了一些东西。

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(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  //Consider this function as your _onNotification and important to note I am using setState() within :)
  void _incrementCounter() {
    print("pressed");  // Does not detect pressed.
    setState(() {
      _counter++;    // counter is not increased
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(
          widget.title,
          style: TextStyle(color: Colors.white),
        ),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button $_counter times:',
              style: TextStyle(fontSize: 20.0, fontWeight: FontWeight.bold),
            ),
          ],
        ),
      ),
      floatingActionButton: MyFloatButton(
          _incrementCounter), //Pass delegate to _incrementCounter method
    );
  }
}

class MyFloatButton extends StatefulWidget {

  // Here I am receiving the function in constructor as params
  const MyFloatButton(this.onPressedFunction, {super.key});

  // Should be the delegated function from _MyHomePageState
  final Function onPressedFunction;

  @override
  _MyFloatButtonState createState() => new _MyFloatButtonState();
}

class _MyFloatButtonState extends State<MyFloatButton> {
  @override
  Widget build(BuildContext context) {
    return Container(
      padding: EdgeInsets.all(5.0),
      decoration: BoxDecoration(
          color: Colors.orangeAccent,
          borderRadius: new BorderRadius.circular(50.0)),
      child: IconButton(
        icon: Icon(Icons.add),
        color: Colors.white,
        onPressed: () => {
          //print('pressed')  // Does work shows button pressed
          widget.onPressedFunction
        }, // call the delegated method to detect the pressed
      ),
    );
  }
}

尝试的事情：

onPressed: widget.onPressedFunction()

结果
生成期间调用了setState（）或NeedmarksBuild

onPressed: widget.onPressedFunction

结果
参数类型“Function”不能分配给参数类型“void Function（）？”。

onPressed: () => widget.onPressedFunction,

结果
不改变什么也做不了