自定义 controller

import 'package:flutter/material.dart';

class CustomComponent extends StatelessWidget {
  final bool isHidden;

  CustomComponent({required this.isHidden});

  @override
  Widget build(BuildContext context) {
    return Visibility(
      visible: !isHidden,
      child: Container(
        width: 200,
        height: 200,
        color: Colors.blue,
        child: Center(
          child: Text(
            'Custom Component',
            style: TextStyle(
              fontSize: 20,
              color: Colors.white,
            ),
          ),
        ),
      ),
    );
  }
}

class CustomController {
  late VoidCallback _listener;
  bool _isHidden = false;

  bool get isHidden => _isHidden;

  set isHidden(bool value) {
    _isHidden = value;
    _listener();
  }

  void addListener(VoidCallback listener) {
    _listener = listener;
  }

  void removeListener() {
    _listener = () {};
  }
}

class CustomScreen extends StatefulWidget {
  @override
  _CustomScreenState createState() => _CustomScreenState();
}

class _CustomScreenState extends State<CustomScreen> {
  late CustomController _controller;

  @override
  void initState() {
    super.initState();
    _controller = CustomController();
    _controller.addListener(_handleControllerChange);
  }

  @override
  void dispose() {
    _controller.removeListener();
    super.dispose();
  }

  void _handleControllerChange() {
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Custom Component Demo'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            CustomComponent(
              isHidden: _controller.isHidden,
            ),
            SizedBox(height: 20),
            ElevatedButton(
              onPressed: () {
                _controller.isHidden = !_controller.isHidden;
              },
              child: Text(
                _controller.isHidden ? 'Show' : 'Hide',
              ),
            ),
          ],
        ),
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: CustomScreen(),
  ));
}

将`CustomController`实例化为`_controller`，并在初始化和销毁阶段添加/移除监听器。在`build`方法中，我们使用`CustomComponent`来展示自定义组件，并使用`_controller.isHidden`来传递是否隐藏组件的状态。

通过点击按钮，我们可以通过控制器的`isHidden`属性来切换组件的隐藏状态。每当`isHidden`属性发生变化时，控制器的监听器会被调用