在 Flutter 混合开发中，Android 原生层通知 Dart 界面更新状态

在 Flutter 混合开发中，Android 原生层通知 Dart 界面更新状态，主要通过MethodChannel的invokeMethod从原生调用 Dart，或者使用EventChannel建立持续的数据流。

方案一：MethodChannel 单向通知（简单场景）

Android 原生层调用 Dart

// MainActivity.kt 或 Service.ktimportio.flutter.plugin.common.MethodChannelclassMainActivity:FlutterActivity(){privatelateinitvarchannel:MethodChanneloverridefunconfigureFlutterEngine(flutterEngine:FlutterEngine){super.configureFlutterEngine(flutterEngine)channel=MethodChannel(flutterEngine.dartExecutor.binaryMessenger,"flutter_launcher")// Dart 调用原生的处理器channel.setMethodCallHandler{call,result->when(call.method){"getSystemInfo"->result.success(getSystemInfo())else->result.notImplemented()}}}/** * 主动通知 Dart 更新（例如：电池变化、应用安装/卸载） */funnotifyDart(event:String,data:Map<String,Any>){// 在主线程调用runOnUiThread{channel.invokeMethod(event,data)}}/** * 示例：电池变化时通知 Dart */funonBatteryChanged(level:Int){notifyDart("onBatteryChanged",mapOf("level"tolevel))}/** * 示例：应用安装/卸载时通知 Dart */funonAppChanged(action:String,packageName:String){notifyDart("onAppChanged",mapOf("action"toaction,// "installed" | "uninstalled" | "updated""package"topackageName))}}

Dart 层接收通知

// lib/services/desktop_service.dartimport'dart:async';import'package:flutter/services.dart';classDesktopService{staticconstMethodChannel_channel=MethodChannel('flutter_launcher');// 状态流控制器staticfinal_batteryController=StreamController<int>.broadcast();staticfinal_appChangeController=StreamController<Map<String,dynamic>>.broadcast();// 公开的数据流staticStream<int>getbatteryStream=>_batteryController.stream;staticStream<Map<String,dynamic>>getappChangeStream=>_appChangeController.stream;staticvoidinit(){// 设置方法调用处理器，接收原生通知_channel.setMethodCallHandler(_handleMethodCall);}staticFuture<<dynamic>_handleMethodCall(MethodCallcall)async{switch(call.method){case'onBatteryChanged':finallevel=call.arguments['level']asint?;if(level!=null){_batteryController.add(level);}returnnull;case'onAppChanged':finaldata=call.argumentsasMap<<dynamic,dynamic>;_appChangeController.add({'action':data['action'],'package':data['package'],});returnnull;case'onTimeTick':// 每分钟通知returnnull;case'onWifiChanged':finalenabled=call.arguments['enabled']asbool?;// 通知WiFi状态变化returnnull;default:returnnull;}}// 主动调用原生方法staticFuture<Map<String,dynamic>>getSystemInfo()async{finalresult=await_channel.invokeMethod('getSystemInfo');return_toStringMap(result);}staticFuture<void>launchApp(Stringpackage)async{await_channel.invokeMethod('launchApp',{'package':package});}staticMap<String,dynamic>_toStringMap(dynamicdata){if(data==null)return{};finalmap=dataasMap<<dynamic,dynamic>;returnmap.map((k,v)=>MapEntry(k.toString(),v));}staticvoiddispose(){_batteryController.close();_appChangeController.close();}}

UI 层监听状态变化

// lib/widgets/status_bar.dartimport'package:flutter/material.dart';import'../services/desktop_service.dart';classStatusBarextendsStatefulWidget{constStatusBar({super.key});@overrideState<<StatusBar>createState()=>_StatusBarState();}class_StatusBarStateextendsState<<StatusBar>{int _battery=100;bool _wifi=false;String_time='';@overridevoidinitState(){super.initState();// 初始化服务DesktopService.init();// 监听电池变化（来自原生通知）DesktopService.batteryStream.listen((level){setState(()=>_battery=level);});// 定时刷新时间Stream.periodic(constDuration(seconds:1)).listen((_){setState((){_time='${DateTime.now().hour.toString().padLeft(2, '0')}:''${DateTime.now().minute.toString().padLeft(2, '0')}';});});// 初始加载_loadSystemInfo();}Future<void>_loadSystemInfo()async{finalinfo=awaitDesktopService.getSystemInfo();setState((){_battery=info['battery']??100;_wifi=info['wifi']??false;});}@overrideWidgetbuild(BuildContextcontext){returnContainer(height:36,color:Colors.black.withOpacity(0.6),padding:constEdgeInsets.symmetric(horizontal:12),child:Row(children:[Text(_time,style:constTextStyle(color:Colors.white)),constSpacer(),Icon(_wifi?Icons.wifi:Icons.wifi_off,color:Colors.white,size:18),constSizedBox(width:8),Text('$_battery%',style:constTextStyle(color:Colors.white)),],),);}}

方案二：EventChannel 持续数据流（适合高频数据）

Android 原生层

// service/SystemEventChannel.ktpackagecom.example.flutter_launcher.serviceimportio.flutter.plugin.common.EventChannelimportio.flutter.plugin.common.EventChannel.EventSinkclassSystemEventChannel:EventChannel.StreamHandler{privatevareventSink:EventSink?=nulloverridefunonListen(arguments:Any?,events:EventSink?){eventSink=eventsstartListening()}overridefunonCancel(arguments:Any?){eventSink=nullstopListening()}/** * 发送事件到 Dart */funsendEvent(event:String,data:Any){eventSink?.success(mapOf("event"toevent,"data"todata))}privatefunstartListening(){// 注册系统监听器（电池、WiFi、时间等）}privatefunstopListening(){// 注销监听器}}

Dart 层

// lib/services/event_service.dartimport'dart:async';import'package:flutter/services.dart';classEventService{staticconstEventChannel_eventChannel=EventChannel('flutter_launcher/events');staticStream<Map<String,dynamic>>?_eventStream;staticStream<Map<String,dynamic>>geteventStream{_eventStream??=_eventChannel.receiveBroadcastStream().map((event){finalmap=eventasMap<<dynamic,dynamic>;return{'event':map['event'],'data':map['data'],};});return_eventStream!;}}

方案三：BroadcastReceiver + 通知（系统事件）

Android 原生层监听系统广播

// receiver/SystemEventReceiver.ktpackagecom.example.flutter_launcher.receiverimportandroid.content.BroadcastReceiverimportandroid.content.Contextimportandroid.content.Intentimportandroid.content.IntentFilterimportandroid.os.BatteryManagerclassSystemEventReceiver(privatevalonEvent:(String,Map<String,Any>)->Unit):BroadcastReceiver(){funregister(context:Context){valfilter=IntentFilter().apply{addAction(Intent.ACTION_BATTERY_CHANGED)addAction(Intent.ACTION_TIME_TICK)addAction(Intent.ACTION_TIME_CHANGED)addAction(Intent.ACTION_PACKAGE_ADDED)addAction(Intent.ACTION_PACKAGE_REMOVED)addAction(Intent.ACTION_PACKAGE_REPLACED)addAction("android.net.wifi.STATE_CHANGE")}context.registerReceiver(this,filter)}fununregister(context:Context){context.unregisterReceiver(this)}overridefunonReceive(context:Context,intent:Intent){when(intent.action){Intent.ACTION_BATTERY_CHANGED->{vallevel=intent.getIntExtra(BatteryManager.EXTRA_LEVEL,-1)valscale=intent.getIntExtra(BatteryManager.EXTRA_SCALE,-1)valpercent=(level*100/scale).coerceIn(0,100)onEvent("battery",mapOf("level"topercent))}Intent.ACTION_TIME_TICK,Intent.ACTION_TIME_CHANGED->{onEvent("time",mapOf("time"toSystem.currentTimeMillis()))}Intent.ACTION_PACKAGE_ADDED->{valpackageName=intent.data?.schemeSpecificPart?:""onEvent("app_added",mapOf("package"topackageName))}Intent.ACTION_PACKAGE_REMOVED->{valpackageName=intent.data?.schemeSpecificPart?:""onEvent("app_removed",mapOf("package"topackageName))}"android.net.wifi.STATE_CHANGE"->{valwifiManager=context.getSystemService(Context.WIFI_SERVICE)asandroid.net.wifi.WifiManageronEvent("wifi",mapOf("enabled"towifiManager.isWifiEnabled))}}}}

在 Service 或 Activity 中使用

classMainActivity:FlutterActivity(){privatelateinitvareventReceiver:SystemEventReceiverprivatelateinitvarchannel:MethodChanneloverridefunonCreate(savedInstanceState:Bundle?){super.onCreate(savedInstanceState)channel=MethodChannel(flutterEngine!!.dartExecutor.binaryMessenger,"flutter_launcher")// 初始化广播接收器eventReceiver=SystemEventReceiver{event,data->// 通知 DartrunOnUiThread{channel.invokeMethod("onSystemEvent",mapOf("event"toevent,"data"todata))}}eventReceiver.register(this)}overridefunonDestroy(){eventReceiver.unregister(this)super.onDestroy()}}

完整状态更新流程图

┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐ │ Android 系统 │ │ Android 原生层 │ │ Flutter Dart │ │ │ │ │ │ │ │ 电池变化 │────→│ BroadcastReceiver│────→│ MethodChannel │ │ 时间变化 │ │ 或 Service 监听 │ │ setMethodCallHandler │ 应用安装/卸载 │ │ │ │ │ │ WiFi状态变化 │ │ │ │ StreamController │ │ │ │ │ 通知 UI 更新 │ └─────────────────┘ └─────────────────┘ └─────────────────┘ ↑ │ 主动查询 ┌────┴────┐ │ invokeMethod │ getSystemInfo └─────────┘

推荐用法总结