本文将通过BasicMessageChannel获取app版本号,以此来演练BasicMessageChannel用法。
- 建立channel
flutter代码:
//建立通道
BasicMessageChannel basicMessageChannel = BasicMessageChannel("com.xmg.basicMessageChannel",StringCodec());
ohos代码:
//定义BasicMessageChannel
private basicMessageChannel: BasicMessageChannel<String> | null = null
//建立通道
this.basicMessageChannel = new BasicMessageChannel(flutterEngine.getDartExecutor(), "com.xmg.basicMessageChannel", StringCodec.INSTANCE)
- 消息发送
消息发送由flutter发送,flutter代码如下:
//发送消息给ohos,并接收ohos返回的消息
void _sendMessage(String sendMessage) async{
ohosResultToFlutter = await basicMessageChannel.send(sendMessage);
setState(() {
});
}
- 消息处理
ohos接收消息,打印log,并且返回应用版本号给flutter
Dart
//消息处理,接收来自flutter的消息
this.basicMessageChannel.setMessageHandler({
onMessage(message,reply) {
console.log("收到来自Flutter的消息: " + message)
let bundleFlags = bundleManager.BundleFlag.GET_BUNDLE_INFO_WITH_APPLICATION;
bundleManager.getBundleInfoForSelf(bundleFlags, (err, data) => {
// 获取应用的版本名(versionName)
const versionName = data.versionName;
reply.reply(versionName);
})
}
})
log输出打印收到来自Flutter的消息: flutter发送消息到ohos
- flutter展示版本号
- 完整代码
flutter代码:
Dart
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'BasicMessageChannel获取app版本号'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({super.key, required this.title});
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
//建立通道
BasicMessageChannel basicMessageChannel = BasicMessageChannel("com.xmg.basicMessageChannel",StringCodec());
//展示ohos返回结果
String ohosResultToFlutter = "";
//发送消息给ohos,并接收ohos返回的消息
void _sendMessage(String sendMessage) async{
ohosResultToFlutter = await basicMessageChannel.send(sendMessage);
setState(() {
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
if (ohosResultToFlutter.isNotEmpty)Text(
"收到来自ohos的消息为:"+ohosResultToFlutter,
),
ElevatedButton(onPressed: () {
_sendMessage("flutter发送消息到ohos");
}, child: Text("发送消息"))
],
),
),
);
}
}
ohos代码:
Dart
import {
BasicMessageChannel,
FlutterAbility, FlutterEngine, MethodCall, MethodChannel, MethodResult,
StringCodec } from '@ohos/flutter_ohos';
import { GeneratedPluginRegistrant } from '../plugins/GeneratedPluginRegistrant';
import deviceInfo from '@ohos.deviceInfo'
import { bundleManager } from '@kit.AbilityKit'
export default class EntryAbility extends FlutterAbility {
private channel: MethodChannel | null = null
//定义BasicMessageChannel
private basicMessageChannel: BasicMessageChannel<String> | null = null
configureFlutterEngine(flutterEngine: FlutterEngine) {
super.configureFlutterEngine(flutterEngine)
GeneratedPluginRegistrant.registerWith(flutterEngine)
this.channel = new MethodChannel(flutterEngine.dartExecutor.getBinaryMessenger(), 'com.xmg.test')
this.channel.setMethodCallHandler({
onMethodCall(call: MethodCall, result: MethodResult): void {
switch (call.method) {
case 'getDeviceInfo':
result.success(deviceInfo.displayVersion);
break;
default:
result.notImplemented
break;
}
}
});
//建立通道
this.basicMessageChannel = new BasicMessageChannel(flutterEngine.getDartExecutor(), "com.xmg.basicMessageChannel", StringCodec.INSTANCE)
//消息处理,接收来自flutter的消息
this.basicMessageChannel.setMessageHandler({
onMessage(message,reply) {
console.log("收到来自Flutter的消息: " + message)
let bundleFlags = bundleManager.BundleFlag.GET_BUNDLE_INFO_WITH_APPLICATION;
bundleManager.getBundleInfoForSelf(bundleFlags, (err, data) => {
// 获取应用的版本名(versionName)
const versionName = data.versionName;
reply.reply(versionName);
})
}
})
}
}