Flutter 混合开发系列 蕴含如下：
- 嵌入原生View-Android
- 嵌入原生View-iOS
- 与原生通信-MethodChannel
- 与原生通信-BasicMessageChannel
- 与原生通信-EventChannel
- 增加 Flutter 到 Android Activity
- 增加 Flutter 到 Android Fragment
- 增加 Flutter 到 iOS
每个工作日分享一篇，欢送关注、点赞及转发。
EventChannel
Flutter 端
Flutter 端创立 EventChannel 通道，用于与原生端通信：
var _eventChannel = EventChannel('com.flutter.guide.EventChannel');com.flutter.guide.EventChannel 是 EventChannel 的名称，原生端要与之对应。
监听原生端发送的音讯：
var _data; @override void initState() { super.initState(); _eventChannel.receiveBroadcastStream().listen(_onData); } _onData(event){ setState(() { _data = event; }); }Flutter 端残缺代码：
class EventChannelDemo extends StatefulWidget { @override _EventChannelDemoState createState() => _EventChannelDemoState();}class _EventChannelDemoState extends State<EventChannelDemo> { var _eventChannel = EventChannel('com.flutter.guide.EventChannel'); var _data; @override void initState() { super.initState(); _eventChannel.receiveBroadcastStream().listen(_onData); } _onData(event){ setState(() { _data = event; }); } @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar(), body: Center( child: Text('$_data'), ), ); }}Android 端
android 下创立 EventChannelDemo：
class EventChannelDemo(var activity: Activity, messenger: BinaryMessenger):EventChannel.StreamHandler { private var channel: EventChannel private var index = 0 private var events: EventChannel.EventSink? = null init { channel = EventChannel(messenger, "com.flutter.guide.EventChannel") channel.setStreamHandler(this) startTimer() } fun startTimer() { var timer = Timer().schedule(timerTask { index++ var map = mapOf("name" to "laomeng${index}", "age" to "${index}" ) activity.runOnUiThread { events?.success(map) } }, 0, 1000) } override fun onListen(arguments: Any?, events: EventChannel.EventSink?) { this.events = events } override fun onCancel(arguments: Any?) { this.events = null }}events?.success(map) 办法是向 Flutter 端发送数据，此办法必须在主线程执行：
activity.runOnUiThread { events?.success(map)}在 MainActivity 启动：
class MainActivity : FlutterActivity() { override fun configureFlutterEngine(flutterEngine: FlutterEngine) { super.configureFlutterEngine(flutterEngine) EventChannelDemo(this,flutterEngine.dartExecutor.binaryMessenger) flutterEngine.plugins.add(MyPlugin()) }}iOS 端
ios 下创立 MethodChannelDemo，按如下形式：
import Flutterimport UIKitpublic class EventChannelDemo:NSObject, FlutterStreamHandler{ var channel:FlutterEventChannel? var count = 0 var events:FlutterEventSink? public override init() { super.init() } convenience init(messenger: FlutterBinaryMessenger) { self.init() channel = FlutterEventChannel(name: "com.flutter.guide.EventChannel", binaryMessenger: messenger) channel?.setStreamHandler(self) startTimer() } func startTimer() { let timer = Timer.scheduledTimer(timeInterval:1, target: self, selector:#selector(self.tickDown),userInfo:nil,repeats: true) } @objc func tickDown(){ count += 1 let args = ["count":count] if(events != nil){ events!(args) } } public func onListen(withArguments arguments: Any?, eventSink events: @escaping FlutterEventSink) -> FlutterError? { self.events = events return nil; } public func onCancel(withArguments arguments: Any?) -> FlutterError? { self.events = nil return nil; }}在 AppDelegate 启动：
import UIKitimport Flutter@UIApplicationMain@objc class AppDelegate: FlutterAppDelegate { override func application( _ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? ) -> Bool { let controller : FlutterViewController = window?.rootViewController as! FlutterViewController EventChannelDemo(messenger: controller.binaryMessenger) GeneratedPluginRegistrant.register(with: self) return super.application(application, didFinishLaunchingWithOptions: launchOptions) }}交换
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