如何在bottomNavigationBar的onPressed时设置材质按钮的状态

import 'package:flutter/material.dart';

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  bool isButtonPressed = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      bottomNavigationBar: BottomNavigationBar(
        items: [
          BottomNavigationBarItem(
            icon: Icon(Icons.home),
            title: Text('Home'),
          ),
          BottomNavigationBarItem(
            icon: MaterialButton(
              onPressed: () {
                setState(() {
                  isButtonPressed = !isButtonPressed;
                });
              },
              color: isButtonPressed ? Colors.red : Colors.blue,
              child: Text('Button'),
            ),
            title: Text('Button'),
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.settings),
            title: Text('Settings'),
          ),
        ],
      ),
    );
  }
}