1️⃣ MethodChannel（请求-响应模型）

异步请求形式，通信模型如下：

Flutter  → invokeMethod() →  Native
Flutter  ← result.success() ← Native

Flutter代码

const channel = MethodChannel("demo");
final result = await channel.invokeMethod("getBattery");

Native的iOS端

channel.setMethodCallHandler { call, result in
    if call.method == "getBattery" {
        result(80)
    }
}

2️⃣ EventChannel（流式数据）

适合：

• 传感器数据
• 定位更新
• 下载进度
• 监听系统状态

单向流：Native → Flutter，通信模型如下：

Native → EventSink → Flutter Stream

在Flutter端只管接收即可

const eventChannel = EventChannel("demo_event");
eventChannel.receiveBroadcastStream().listen((event) {
  print(event);
});

3️⃣ BasicMessageChannel（双向消息）

最底层、最灵活！适合：

• 自定义协议
• 双向频繁通信
• 纯文本、JSON 或 binary 数据

通信模型

Flutter  ←──────────────→  Native
        BasicMessageChannel

flutter端代码

static const channel = BasicMessageChannel<String>("basic_demo", StringCodec());

  Future<void> sendMessage() async {
    final response = await channel.send(controller.text);
    setState(() {
      result = response ?? "No response";
    });
  }

  @override
  void initState() {
    super.initState();

    // 监听 Native 主动发来的消息
    channel.setMessageHandler((message) async {
      return "Flutter received: $message";
    });
  }

Native端，以iOS的Swift举例子

import Flutter

func registerBasicChannel(engine: FlutterEngine) {

    let channel = FlutterBasicMessageChannel(
        name: "basic_demo",
        binaryMessenger: engine.binaryMessenger,
        codec: FlutterStringCodec.sharedInstance()
    )

    channel.setMessageHandler { message, reply in

        if let text = message as? String {
            let processed = text.uppercased()
            reply(processed) // 单条消息回复
        } else {
            reply("Invalid message")
        }
    }

    // 也可以 Native 主动发消息到Flutter
    DispatchQueue.main.asyncAfter(deadline: .now() + 5) {
        channel.sendMessage("Hello from Native")
    }
}