flutter和安卓通信(2)

import 'dart:async';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() {
  runApp(PlatformView());
}

class PlatformView extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Platform View',
      theme: ThemeData(
        primarySwatch: Colors.grey,
      ),
      home: const MyHomePage(title: 'Platform View'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  static const MethodChannel _methodChannel =
      MethodChannel('samples.flutter.io/platform_view');

  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  Future<void> _launchPlatformCount() async {
    final int platformCounter =
        await _methodChannel.invokeMethod('switchView', _counter);
    setState(() {
      _counter = platformCounter;
    });
  }

  @override
  Widget build(BuildContext context) => Scaffold(
        appBar: AppBar(
          title: Text(widget.title),
        ),
        body: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: <Widget>[
            Expanded(
              child: Center(
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: <Widget>[
                    Text(
                      'Button tapped $_counter time${ _counter == 1 ? '' : 's' }.',
                      style: const TextStyle(fontSize: 17.0),
                    ),
                    Padding(
                      padding: const EdgeInsets.all(18.0),
                      child: RaisedButton(
                          child: Platform.isIOS
                              ? const Text('Continue in iOS view')
                              : const Text('Continue in Android view'),
                          onPressed: _launchPlatformCount),
                    ),
                  ],
                ),
              ),
            ),
            Container(
              padding: const EdgeInsets.only(bottom: 15.0, left: 5.0),
              child: Row(
                children: <Widget>[
                  Image.asset('assets/flutter-mark-square-64.png',
                      scale: 1.5),
                  const Text(
                    'Flutter',
                    style: TextStyle(fontSize: 30.0),
                  ),
                ],
              ),
            ),
          ],
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: _incrementCounter,
          tooltip: 'Increment',
          child: const Icon(Icons.add),
        ),
      );
}

import android.content.Intent;
import androidx.annotation.NonNull;
import io.flutter.embedding.android.FlutterActivity;
import io.flutter.embedding.engine.FlutterEngine;
import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugins.GeneratedPluginRegistrant;

public class MainActivity extends FlutterActivity {
  private static final String CHANNEL = "samples.flutter.io/platform_view";
  private static final String METHOD_SWITCH_VIEW = "switchView";
  private static final int COUNT_REQUEST = 1;

  private MethodChannel.Result result;

  @Override
  public void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {
    new MethodChannel(flutterEngine.getDartExecutor(), CHANNEL).setMethodCallHandler(
      new MethodChannel.MethodCallHandler() {
        @Override
        public void onMethodCall(MethodCall methodCall, MethodChannel.Result result) {
          MainActivity.this.result = result;
          int count = methodCall.arguments();
          if (methodCall.method.equals(METHOD_SWITCH_VIEW)) {
            onLaunchFullScreen(count);
          } else {
            result.notImplemented();
          }
        }
      }
    );
  }

  private void onLaunchFullScreen(int count) {
    Intent fullScreenIntent = new Intent(this, CountActivity.class);
    fullScreenIntent.putExtra(CountActivity.EXTRA_COUNTER, count);
    startActivityForResult(fullScreenIntent, COUNT_REQUEST);
  }

  @Override
  protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == COUNT_REQUEST) {
      if (resultCode == RESULT_OK) {
        result.success(data.getIntExtra(CountActivity.EXTRA_COUNTER, 0));
      } else {
        result.error("ACTIVITY_FAILURE", "Failed while launching activity", null);
      }
    }
  }
}