flutter如何在单击时更改按钮的颜色

import 'package:flutter/material.dart';

class ColorfulButton extends StatefulWidget {
  @override
  _ColorfulButtonState createState() => _ColorfulButtonState();
}

class _ColorfulButtonState extends State<ColorfulButton> {
  Color _buttonColor = Colors.blue;

  void _changeColor() {
    setState(() {
      _buttonColor = Colors.red;
    });
  }

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: _changeColor,
      child: Container(
        width: 200,
        height: 50,
        color: _buttonColor,
        child: Center(
          child: Text(
            'Click me',
            style: TextStyle(color: Colors.white),
          ),
        ),
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: Scaffold(
      appBar: AppBar(
        title: Text('Colorful Button'),
      ),
      body: Center(
        child: ColorfulButton(),
      ),
    ),
  ));
}