Channel实现Flutter与原生平台之间的双向通信

文章目录

（一）通过MessageChannel实现Flutter与原生平台之间的双向通信
- Flutter端实现MessageChannel通信步骤：
- Android端实现MessageChannel通信步骤：
（二）通过MethodChannel实现Flutter与原生平台之间的双向通信
- Flutter端实现MessageChannel通信步骤：
- Android端实现MessageChannel通信步骤：
（三）通过EventChannel实现Flutter与原生平台之间的双向通信
- Flutter端实现EventChannel通信步骤：
- Android端实现EventChannel通信步骤：

首先，现在Android中进行注册与初始化：

    private void registerChannelFunction() {FlutterEngine flutterEngine = getFlutterEngine();if (flutterEngine == null) {Log.e("ERROR", "注册消息通道失败 FlutterEngine = null");return;}DartExecutor dartExecutor = flutterEngine.getDartExecutor();binaryMessenger = dartExecutor.getBinaryMessenger();messageChannelSendFunction();methodChannelSendFunction();eventChannelSendFunction();}

（一）通过MessageChannel实现Flutter与原生平台之间的双向通信

Flutter端实现MessageChannel通信步骤：

先定义messageChannel

static const basicMethodChannel = 
BasicMessageChannel("flutter_basic_method_channel", StandardMessageCodec());

发送message：

  Future<void> sendMessage(Map json) async {await basicMethodChannel.send(json);}

接收message：

  void receiveMessage() {basicMethodChannel.setMessageHandler((result) async {Map? map = result as Map?;int code = map?["code"];String message=map?["message"];setState(() {receive = "messageChannel receiveMessage 中的回调 code $code  message $message";print(receive);print("receiveMessage: code:$code message:$message");});return 'Flutter 已收到消息';});}

Android端实现MessageChannel通信步骤：

首先，先初始化 BasicMessageChannel 实例对象：

basicMessageChannel = new BasicMessageChannel<>(binaryMessenger, 
"flutter_basic_method_channel", StandardMessageCodec.INSTANCE);

然后为Message对象设置MessageHandler对象：

        basicMessageChannel.setMessageHandler(new BasicMessageChannel.MessageHandler() {@Overridepublic void onMessage(@Nullable Object message, @NonNull BasicMessageChannel.Reply reply) {System.out.println("flutter 传来的数据为: "+message.toString());basicSendMessage();}});

（二）通过MethodChannel实现Flutter与原生平台之间的双向通信

Flutter端实现MessageChannel通信步骤：

定义methodChannel：

static const methodChannel = MethodChannel("flutter_method_channel");

然后通过methodChannel的invokeMethod进行消息的发送：

  static Future<dynamic> invokeNative(String method,{required Map<String, String> arguments}) async {if (arguments == null) {return await methodChannel.invokeMethod(method);} else {return await methodChannel.invokeMethod(method, arguments);}}

最后调用会返回一个结果，通过这个result拿到返回的数据：

    Map result = await invokeNative("test", arguments: {});int code = result["code"];String message = result["message"];setState(() {receive = "invokeNative 中的回调 code $code message $message";print(receive);});

Android端实现MessageChannel通信步骤：

先初始化MethodChannel的实例：

        mMethodChannel = new MethodChannel(binaryMessenger, channelName);

然后设置methodHandler，它会重写MethodCallHandler的onMethodCall方法：

    private MethodChannel.MethodCallHandler getMethodCallHandler() {return new MethodChannel.MethodCallHandler() {@Overridepublic void onMethodCall(@NonNull MethodCall call, @NonNull MethodChannel.Result result) {String method = call.method;Object Arguments = call.arguments;Map<String, Object> arguments = null;if (null != Arguments) {arguments = (Map<String, Object>) Arguments;}if ("test".equals(method)) {Toast.makeText(this, "flutter 调用到了 android test 数据为 name :"+arguments.get("name") +" age : "+arguments.get("age"), Toast.LENGTH_SHORT).show();Map<String, Object> objectMap = new HashMap<>();objectMap.put("message", "result.success 返回给flutter的basic数据");objectMap.put("code", 300);result.success(objectMap);} else {result.notImplemented();}}};}

（三）通过EventChannel实现Flutter与原生平台之间的双向通信

Flutter端实现EventChannel通信步骤：

首先初始化EventChannel实例：

static const eventChannel = EventChannel("flutter_event_channel");

然后设置Stream：

    eventChannel.receiveBroadcastStream().listen((event) {// int code = event["code"];// String message = event["message"];setState(() {// receive += "code $code message $message  ";// print("eventMessageListener: "+receive);print(event);});}, onError: (event) {});

Android端实现EventChannel通信步骤：

初始化EventChannel：

String channelName = "flutter_event_channel";
EventChannel eventChannel = new EventChannel(binaryMessenger, channelName);

然后调用setStreamHandler为EventChannel设置一个处理器：

        eventChannel.setStreamHandler(new EventChannel.StreamHandler() {@Overridepublic void onListen(Object arguments, EventChannel.EventSink events) {eventSink = events;startTimer();}@Overridepublic void onCancel(Object arguments) {}});