Flutter與原生的通信(Android/IOS版)

Flutter 官方提供 MethodChannel、EventChannel、BasicMessageChannel 三種方式與原生通信

1.MethodChannel

     特點：單方請求響應（flutter->原生）

  (1) flutter:

static const platform = const MethodChannel('xiaochen.flutter.io/battery');

    try {
      final int result = await platform.invokeMethod('getBatteryLevel');
     
    } on PlatformException catch (e) {
    
    }

   （2）原生：android 

    private static final String battery= "xiaochen.flutter.io/battery";


     new MethodChannel(getFlutterView(), battery).setMethodCallHandler(
                new MethodCallHandler() {
                    @Override
                    public void onMethodCall(MethodCall call, Result result) {
                        // TODO
                        if (call.method.equals("getBatteryLevel")) {
                            //java 核心代碼
                            int batteryLevel = getBatteryLevel(); 
                            if (batteryLevel != -1) {
                                result.success(batteryLevel);
                            } else {
                                result.error("UNAVAILABLE", "Battery level not available.", null);
                            }
                        } else {
                            result.notImplemented();
                        }
                    }
                }
        );

            (3)原生： IOS:

    FlutterViewController* controller = (FlutterViewController*)self.window.rootViewController;
    
    FlutterMethodChannel* batteryChannel = [FlutterMethodChannel
                                            methodChannelWithName:@"xiaochen.flutter.io/battery"
                                            binaryMessenger:controller];
    
    
   
    [batteryChannel setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
        // TODO
        if ([@"getBatteryLevel" isEqualToString:call.method]) {

             //IOS 核心代碼
            int batteryLevel = [self getBatteryLevel];
            
            if (batteryLevel == -1) {

                result([FlutterError errorWithCode:@"UNAVAILABLE"
                                           message:@"Battery info unavailable"
                                           details:nil]);
            } else {
                result(@(batteryLevel));
            }
        } else {
            result(FlutterMethodNotImplemented);
        }
    }];

2.EventChannel

     特點：接收數據（原生->flutter）

  (1) flutter:

 static const EventChannel _eventChannel =
      const EventChannel('xiaochen.flutter.io/test');

   // 監聽開始
    _eventChannel.receiveBroadcastStream().listen(_onEvent, onError: _onError);

    
  void _onEvent(Object event) {
    print('返回的內容: $event');
   }

  void _onError(Object error) {
    print('返回的錯誤');
  }


   

   

     (2) 原生：android

  private static final String test= "xiaochen.flutter.io/test";

  private EventChannel.EventSink eventSink;

   new EventChannel(getFlutterView(), test).setStreamHandler(
                new EventChannel.StreamHandler() {
                    @Override
                    public void onListen(Object o, EventChannel.EventSink eventSink) {
                        this.eventSink = eventSink;

                        eventSink.success("主動發送消息給flutter");
                    }

                    @Override
                    public void onCancel(Object o) {

                    }


                }
        );

     (3)原生： IOS:

      

    FlutterViewController* controller = (FlutterViewController*)self.window.rootViewController;

    FlutterEventChannel* eventChannel = [FlutterEventChannel eventChannelWithName:@"xiaochen.flutter.io/test" binaryMessenger:controller];
    [eventChannel setStreamHandler:self];




//回調函數：
    FlutterEventSink     eventSink;

 - (FlutterError* _Nullable)onListenWithArguments:(id _Nullable)arguments
                                       eventSink:(FlutterEventSink)events {
       eventSink = events;
    
       if (events) {
          events(@"主動發送通知到flutter");
       }

     return nil;
    }



    /// flutter不再接收
- (FlutterError* _Nullable)onCancelWithArguments:(id _Nullable)arguments {
 
    [[NSNotificationCenter defaultCenter] removeObserver:self];
    eventSink = nil;
    return nil;
}

 

3.BasicMessageChannel

  特點：雙通道

     (1)flutter:

//發送
static const SendMessage = const BasicMessageChannel('xiaochen.flutter.io/message', StandardMessageCodec());

  Future<String> sendMessage() async {
    String reply = await SendMessage.send('發送給Native端的數據');
    return reply;
  }


//接收
  static const ReceiveMessage = const BasicMessageChannel('xiaochen.flutter.io/message2', StandardMessageCodec());

  void receiveMessage() {
    ReceiveMessage.setMessageHandler((message) async {
      print('receiveMessage: $message');
      return '返回Native端的數據';
    });
  }

       (2)原生 android:

      

       BasicMessageChannel<Object> messageChannel = new BasicMessageChannel<Object>(getFlutterView(), "xiaochen.flutter.io/message", StandardMessageCodec.INSTANCE);


        // 接收消息監聽
        messageChannel.setMessageHandler(new BasicMessageChannel.MessageHandler<Object>() {
            @Override
            public void onMessage(Object o, BasicMessageChannel.Reply<Object> reply) {
                System.out.println("onMessage: " + o);
                reply.reply("返回給flutter的數據");
            }
        });




        BasicMessageChannel<Object> messageChannel2 = new BasicMessageChannel<Object>(getFlutterView(), "samples.flutter.io/message2", StandardMessageCodec.INSTANCE);

        // 發送消息
        messageChannel2.send("發送給flutter的數據", new BasicMessageChannel.Reply<Object>() {
            @Override
            public void reply(Object o) {

                System.out.println("onReply: " + o);
            }
        });

  (3)原生： IOS:

FlutterViewController* controller = (FlutterViewController*)self.window.rootViewController;

 // 初始化定義
    FlutterBasicMessageChannel* messageChannel = [FlutterBasicMessageChannel messageChannelWithName:@"xiaochen.flutter.io/message" binaryMessenger:controller];
    
    // 接收消息監聽
    [messageChannel setMessageHandler:^(id message, FlutterReply callback) {
        NSLog(message);
        callback(@"返回flutter端的數據");
    }];


    FlutterBasicMessageChannel* messageChannel2 = [FlutterBasicMessageChannel messageChannelWithName:@"xiaochen.flutter.io/message2" binaryMessenger:controller];
    
    // 發送消息
    [messageChannel2 sendMessage:(@"發送給flutter的數據") reply:^(id reply) {
        NSLog(reply);
    }];