直接上代碼：
dart：

class StreamView extends StatefulWidget {
  @override
  _StreamViewState createState() => _StreamViewState();
}

class _StreamViewState extends State<StreamView> {
  var getData;
  void sendChannel()async{
  
    final chanel = MethodChannel('example.send');
    var data = await chanel.invokeMethod('get',['who are you',123]);


    getData = data.toString();
    setState(() {});

  }
  @override
  Widget build(BuildContext context) {
    print('build');

    return Scaffold(
      body: Center(child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          Text(getData??''),
          FlatButton(onPressed: ()=>sendChannel(), child: Text('send'))
        ],
      ),),
    );
  }
}

android >>>>MainActivity.java

public class MainActivity extends FlutterActivity {
    @Override
  public void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {

    GeneratedPluginRegistrant.registerWith(flutterEngine);
//getFlutterView()已經(jīng)被刪除  延欠，使用flutterEngine.getDartExecutor().getBinaryMessenger()替換
        new MethodChannel(flutterEngine.getDartExecutor().getBinaryMessenger(),
                "example.send").setMethodCallHandler(new MyChannel());
  }

}
class  MyChannel implements MethodChannel.MethodCallHandler{

    @Override
    public void onMethodCall(MethodCall call, MethodChannel.Result result) {
        if(call.method.equals("get")){
           result.success("Native Answer");
        }
        if(call.arguments!=null){
            if(call.arguments instanceof ArrayList){
                ArrayList list= (ArrayList) call.arguments;
                String a= (String) list.get(0);
                int b= (int) list.get(1);
                System.out.println(a); // who are you
                System.out.println(b); // 123
            }
        }

    }
}

ios>>> Runner > appdelegate.swift
沒學過swift蛛淋，僅供參考

import UIKit
import Flutter

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    //start
    let controller = window?.rootViewController as! FlutterViewController;
    let channel = FlutterMethodChannel(name: "example.send", binaryMessenger: controller.binaryMessenger);
    channel.setMethodCallHandler { (call, result) in
        if(call.method=="get"){
            result("Native Answer");
        }
    }
    //end
    GeneratedPluginRegistrant.register(with: self)
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
}

參考文檔：Flutter官方 https://flutter.dev/docs/development/platform-integration/platform-channels
]