Flutter原生广播接收插件flutter_broadcast_receiver的使用

Flutter原生广播接收插件flutter_broadcast_receiver的使用

flutter_broadcast_receiver 插件可以帮助你在应用中广播事件。以下是该插件的使用方法。

使用

首先，在 pubspec.yaml 文件中添加依赖：

dependencies:
  flutter_broadcast_receiver: ^1.0.0+2

然后在 Dart 文件中导入包：

import 'package:flutter_broadcast_receiver/flutter_broadcast_receiver.dart';

参数使用

以下是一些常用的参数：

• CUSTOM_EVENT: 必须与发布者匹配的参数键。
• message: 发布者返回的数据。
• <anyDataType>: 发布者返回的数据类型或发送的数据类型。
• argument: 来自发布者的数据（可以是任何数据类型）。

示例代码

以下是一个完整的示例代码，展示了如何订阅、发布和取消订阅广播事件。

import 'package:flutter/material.dart';
import 'package:flutter_broadcast_receiver/flutter_broadcast_receiver.dart';

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

class MyApp extends StatelessWidget {
  // 这个小部件是你的应用的根。
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, this.title}) : super(key: key);
  final String? title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

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

  @override
  void initState() {
    super.initState();
    // 订阅广播
    BroadcastReceiver().subscribe<String>("BROADCAST_RECEIVER_DEMO", (String message) {
      print("BroadcastReceiver() data => $message");
      final snackBar = SnackBar(
        content: Text('Yay! A Broadcast is received\n_counter value is $message'),
      );
      ScaffoldMessenger.of(context).showSnackBar(snackBar);
    });
  }

  @override
  void dispose() {
    // 取消订阅广播
    BroadcastReceiver().unsubscribe("BROADCAST_RECEIVER_DEMO");
    super.dispose();
  }

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
    // 发布广播
    BroadcastReceiver().publish<String>("BROADCAST_RECEIVER_DEMO", arguments: _counter.toString());
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title!),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

解释

1. 订阅广播：

   BroadcastReceiver().subscribe<String>("BROADCAST_RECEIVER_DEMO", (String message) {
     print("BroadcastReceiver() data => $message");
     final snackBar = SnackBar(
       content: Text('Yay! A Broadcast is received\n_counter value is $message'),
     );
     ScaffoldMessenger.of(context).showSnackBar(snackBar);
   });
   

   这段代码订阅了一个名为 "BROADCAST_RECEIVER_DEMO" 的广播，并且当广播被触发时，会在控制台打印消息并在屏幕上显示一个 SnackBar。

2. 取消订阅广播：

   BroadcastReceiver().unsubscribe("BROADCAST_RECEIVER_DEMO");
   

   这段代码取消了对 "BROADCAST_RECEIVER_DEMO" 广播的订阅。

3. 发布广播：

   BroadcastReceiver().publish<String>("BROADCAST_RECEIVER_DEMO", arguments: _counter.toString());