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Flutter

              
                import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('NotificationListener 事件通知 - 自定义事件通知'),
        ),
        body: MyNotificationPage(),
      ),
    );
  }
}

// codepen 演示无效,需要在模拟器或真机上运行

class MyNotification extends Notification {
  final String msg;
  MyNotification(this.msg);
}

class MyNotificationPage extends StatefulWidget {
  @override
  _MyNotificationPageState createState() => _MyNotificationPageState();
}

class _MyNotificationPageState extends State<MyNotificationPage> {
  String _msg = "";
  @override
  Widget build(BuildContext context) {
    return NotificationListener(
      onNotification: (notification) {
        setState(() {
          _msg += notification.msg + ' ';
        });
        return true;
      },
      child: Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            Builder(
              builder: (context) {
                return ElevatedButton(
                  onPressed: () => MyNotification("Hi").dispatch(context),
                  child: Text(
                    "发送通知",
                    style: TextStyle(fontSize: 20),
                  ),
                );
              },
            ),
            Text(
              '收到通知:' + _msg,
              style: TextStyle(fontSize: 16),
            )
          ],
        ),
      ),
    );
  }
}

              
            
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999px

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