Flutter与Android通信方式->MethodChannel方式(发送消息并且返回结果)

摘要：Flutter版本号：1.12.13，Kotlin版本号：1.3.72 

版本号不同，实现的方式不一样，所以特此标注下。

具体的实现原理，自行查阅。这里只写代码实现过程，主要原因是网上Kotlin的实现方式实在太少，特此记录。

Flutter:

import 'package:base_library/base_library.dart'; import 'package:flutter/material.dart'; import 'package:flutter/services.dart'; class ChannelDemoPage extends StatefulWidget { @override _ChannelDemoPageState createState() => _ChannelDemoPageState(); } class _ChannelDemoPageState extends State<ChannelDemoPage> { static const _channel = const MethodChannel('plugins.flutter.io/FlutterMessagePlugin'); @override void initState() { super.initState(); } @override Widget build(BuildContext context) { return new Scaffold( body: new Row( ), floatingActionButtonLocation: FloatingActionButtonLocation.endFloat, floatingActionButton: new FloatingActionButton( backgroundColor: Colors.blueAccent, onPressed: () { this.getResult(); }, child: new Icon(Icons.adb), ), ); } void getResult() async { try { Map<String, Object> map = {"shareUrl": "https://www.baidu.com"}; var result = await _channel.invokeMethod("getRealUrl", map); LogUtil.e("result->$result"); } catch (e) { LogUtil.e("e->, $e"); } } }

Kotlin:

import android.content.Context import android.util.Log import io.flutter.embedding.engine.plugins.FlutterPlugin import io.flutter.plugin.common.* import io.flutter.plugin.common.MethodChannel.MethodCallHandler import io.flutter.plugin.common.MethodChannel.Result class FlutterMessagePlugin : FlutterPlugin, MethodCallHandler { private var channel: MethodChannel? = null private var context: Context? = null override fun onMethodCall(call: MethodCall, result: Result) { if (call.method == "getRealUrl") { var shareUrl = call.argument<String>("shareUrl"); Log.v("shareUrl=", shareUrl) result.success("处理完成") } else { result.notImplemented() } } companion object { var channelName = "plugins.flutter.io/FlutterMessagePlugin"; fun registerWith(registry: PluginRegistry.Registrar) { var flutterPlugin = FlutterMessagePlugin(); flutterPlugin.channel = MethodChannel(registry.messenger(), channelName); flutterPlugin.context = registry.context(); flutterPlugin.channel?.setMethodCallHandler(flutterPlugin); } } override fun onAttachedToEngine(binding: FlutterPlugin.FlutterPluginBinding) { channel = MethodChannel(binding.binaryMessenger, channelName) context = binding.applicationContext channel!!.setMethodCallHandler(this) } override fun onDetachedFromEngine(binding: FlutterPlugin.FlutterPluginBinding) { channel?.setMethodCallHandler(null) channel = null; } } 

import androidx.annotation.NonNull; import io.flutter.embedding.android.FlutterActivity import io.flutter.embedding.engine.FlutterEngine import io.flutter.plugins.GeneratedPluginRegistrant class MainActivity: FlutterActivity () { override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) { flutterEngine.getPlugins().add(FlutterMessagePlugin()); GeneratedPluginRegistrant.registerWith(flutterEngine); } } 

显示结果：

V/shareUrl=: https://www.baidu.com I/flutter: common_utils e result->处理完成