HarmonyOS NEXT-Flutter混合开发之鸿蒙-代码实践

在 Flutter 三端分离模式下完成纯血鸿蒙混入的过程中，虽然官方文档提供了一定的指导，但实际操作中可能会遇到一些坑。以下是我在适配过程中的一些经验总结，供各位开发者参考 😄 如果有帮助点个赞。

在混入过程中是基于咸鱼团队 flutter_boost（这里不讨论和其他方案的差别） 和自定义 FlutterPlugin 实现的。

主要涉及内容：

环境搭建
Flutter module 创建
Futter 引入 flutter_boost
Harmony 引入 flutter_boost
Flutter 与鸿蒙侧通信
Flutter 调用鸿蒙原生
环境搭建
Fluter 环境
准备支持鸿蒙的 Flutter 开发环境，flutter_fluter 仓库基于 Flutter SDK 对于OpenHarmony平台的兼容拓展，可支持 IDE 或者终端使用 Flutter Tools 指令编译和构建 OpenHarmony 应用程序。

Harmonyos NEXT 环境
不再赘述，上链接。

Flutter module 创建
创建 Fluter 项目

flutter create -t module --org xyz.zhousg demo_fluter
打包 Fluter 项目

flutter build har --debug
Fluter 引入 flutter_boost
安装依赖
dependencies:
flutter:

sdk: flutter

# The following adds the Cupertino Icons font to your application.
# Use with the CupertinoIcons class for iOS style icons.
cupertino_icons: ^1.0.2
fl_chart: ^0.62.0
flutter_boost:

• git:
• url: 'https://github.com/alibaba/flutter_boost.git'
• ref: '4.6.5'
  配置路由表
  import 'package:flutter/cupertino.dart';
  import 'package:flutter/material.dart';
  import 'package:flutter_boost/flutter_boost.dart';

// 1. 创建一个自定义的Binding，继承和with的关系如下，里面什么都不用写
class CustomFlutterBinding extends WidgetsFlutterBinding

with BoostFlutterBinding {}

void main() {
// 2. 这里的CustomFlutterBinding调用务必不可缺少，用于控制Boost状态的resume和pause
CustomFlutterBinding();
runApp(const MyApp());
}

class MyApp extends StatefulWidget {
const MyApp({super.key});

@override
State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
// 3. 路由表
Map<String, FlutterBoostRouteFactory> routerMap = {

'SettingsPage': (settings, isContainerPage, uniqueId) {
  return CupertinoPageRoute(
    settings: settings,
    builder: (BuildContext ctx) {
      return const Placeholder();
    },
  );
},
'DeviceStoragePage': (settings, isContainerPage, uniqueId) {
  return CupertinoPageRoute(
    settings: settings,
    builder: (BuildContext ctx) {
      return const Placeholder();
    },
  );
},
'AboutPage': (settings, isContainerPage, uniqueId) {
  return CupertinoPageRoute(
    settings: settings,
    builder: (BuildContext ctx) {
      return const Placeholder();
    },
  );
},
'/': (settings, isContainerPage, uniqueId) {
  return CupertinoPageRoute(
    settings: settings,
    builder: (BuildContext ctx) {
      return const Placeholder();
    },
  );
},

};

// 路由工厂函数
Route<dynamic> routeFactory(

  RouteSettings settings, bool isContainerPage, String? uniqueId) {
FlutterBoostRouteFactory? fn = routerMap[settings.name];
if (fn == null) {
  throw FlutterError(
      'Route "${settings.toString()}" is not defined in routerMap.');
}
return fn(settings, isContainerPage, uniqueId)!;

}

@override
Widget build(BuildContext context) {

// flutter_boost 接管
return FlutterBoostApp(
  routeFactory,
  // Flutter 侧直接预览需要，需要使用 Deveco Studio 导入 .ohos 项目进行自动签名预览至鸿蒙设备
  initialRoute: 'SettingsPage',
  appBuilder: (home) {
    return MaterialApp(
      builder: (context, child) => home,
    );
  },
);

}
}
Harmony 引入 flutter_boost
这里使用的是 router + FlutterPage 方式展示 Flutter 界面, Navigation 后续再说吧~

a. 先打包 Fluter 项目，会生成三个产物

.ohos
|--har

   |-- fluter_boost.har
   |-- fluter_module.har
   |-- fluter.har

b. 在鸿蒙项目中，引入依赖

oh-package.json5

"dependencies": {
"@ohos/flutter_module": "file:../demo_flutter/.ohos/har/flutter_module.har",
// 下面两个依赖我直接拷贝到了 libs 下
"@ohos/flutter_ohos": "file:./libs/flutter.har",
"flutter_boost": "file:./libs/flutter_boost.har"
},
"overrides": {
"@ohos/flutter_ohos": "file:./libs/flutter.har",
"flutter_boost": "file:./libs/flutter_boost.har"
},
c. 初始化 flutter_boost

entryAbility.ets

import { AbilityConstant, ConfigurationConstant, UIAbility, Want } from '@kit.AbilityKit';
import { router } from '@kit.ArkUI';
import { FlutterManager } from '@ohos/flutter_ohos';
import { FlutterBoostDelegate, FlutterBoostRouteOptions, FlutterBoost, FlutterBoostSetupOptionsBuilder } from 'flutter_boost';
import { GeneratedPluginRegistrant } from '@ohos/flutter_module';

export default class EntryAbility extends UIAbility implements FlutterBoostDelegate{
pushNativeRoute(options: FlutterBoostRouteOptions): void {

// throw new Error('Method not implemented.');

}

pushFlutterRoute(options: FlutterBoostRouteOptions,): void {

// throw new Error('Method not implemented.');

}

popRoute(options: FlutterBoostRouteOptions): boolean {

// throw new Error('Method not implemented.');
router.back()
return true

}

async onCreate(want: Want, launchParam: AbilityConstant.LaunchParam) {

FlutterManager.getInstance().pushUIAbility(this);

}

onDestroy(): void {

FlutterManager.getInstance().popUIAbility(this);

}

onWindowStageCreate(windowStage: window.WindowStage): void {

// Flutter bind in UIAbility
FlutterManager.getInstance().pushWindowStage(this, windowStage);
// Initial FlutterBoost
const optionsBuilder: FlutterBoostSetupOptionsBuilder = new FlutterBoostSetupOptionsBuilder()
FlutterBoost.getInstance().setup(this, this.context, (engine) => {
  GeneratedPluginRegistrant.registerWith(engine)
}, optionsBuilder.build())

windowStage.loadContent('pages/Index');

}

onWindowStageDestroy(): void {

FlutterManager.getInstance().popWindowStage(this);

}

onForeground(): void {

logger.info('Ability onForeground');

}

onBackground(): void {

logger.info('Ability onBackground');

}
}
这里部分代码省略了 ~ pushNativeRoute pushFlutterRoute popRoute 具体实现还是参考官方仓库

d. Flutter容器与跳转

FlutterPage 承载Flutter的页面
pages/FluterPage.ets

import { FlutterEntry, FlutterPage, FlutterView} from '@ohos/flutter_ohos';
import { FlutterBoost, FlutterBoostEntry } from 'flutter_boost';
import { router } from '@kit.ArkUI';

@Entry
@Component
struct SettingsPage {
private flutterEntry?: FlutterEntry;
private flutterView?: FlutterView

aboutToAppear() {

this.flutterEntry = new FlutterBoostEntry(getContext(this), router.getParams())
this.flutterEntry?.aboutToAppear()
this.flutterView = this.flutterEntry?.getFlutterView()

}

aboutToDisappear() {

this.flutterEntry?.aboutToDisappear()

}

onPageShow() {

this.flutterEntry?.onPageShow()

}

onPageHide() {

this.flutterEntry?.onPageHide()

}

onBackPress(): boolean | void {

FlutterBoost.getInstance()
  .getPlugin()?.onBackPressed();
return true;

}

build() {

Column() {
  FlutterPage({ viewId: this.flutterView?.getId() })
    .width('100%')
    .height('100%')
}
.width('100%')
.height('100%')

}
}
在 Index 中的跳转
pages/Index.ets

// uri Flutter Module 中的路由表 KEY params 是传参
router.pushUrl({ url: 'pages/FlutterPage', params: { uri: 'DeviceStoragePage', params: {} } })
router.pushUrl({ url: 'pages/FlutterPage', params: { uri: 'SettingPage', params: {} } })
router.pushUrl({ url: 'pages/FlutterPage', params: { uri: 'AboutPage', params: {} } })
Flutter 与鸿蒙侧通信
Flutter侧
TextButton(

onPressed: () {
  Map<String, String> data = {'name': 'jack'};
  BoostChannel.instance.sendEventToNative('updateUser', data);
},
child: const Text('发送消息'),

),
鸿蒙侧
pages/FlutterPage.ets

aboutToAppear() {
this.flutterEntry = new FlutterBoostEntry(getContext(this), router.getParams())
this.flutterEntry?.aboutToAppear()
this.flutterView = this.flutterEntry?.getFlutterView()

const plugin = FlutterBoost.getInstance()

.getPlugin()

if (plugin) {

// 通信
plugin.addEventListener('updateUser', {
  onEvent: (key, args) => {
    // logger.debug(`事件名称 ${key}`, JSON.stringify(args))
    promptAction.showToast({ message: 'Flutter Data: ' + JSON.stringify(args) })
  }
})

}
Flutter 调用鸿蒙原生
Flutter侧
final _platform = const MethodChannel('xyz.zhousg.interview_success_project');
TextButton(

onPressed: () {
  _platform.invokeMethod('openCamera').then(
        (value) => setState(() {
          // value 鸿蒙侧回传数据
        }),
      );
},
child: Text('打开相机),

),
鸿蒙侧
定义 Flutter 插件

NativePlugin.ets

import { FlutterPlugin, FlutterPluginBinding, MethodChannel, MethodResult } from '@ohos/flutter_ohos';

export class NativePlugin implements FlutterPlugin {
private channel?: MethodChannel;

getUniqueClassName(): string {

return 'CameraPlugin'

}

onAttachedToEngine(binding: FlutterPluginBinding): void {

this.channel = new MethodChannel(binding.getBinaryMessenger(), 'xyz.zhousg.interview_success_project')
this.channel.setMethodCallHandler({
  onMethodCall: (call, result) => {
    switch (call.method) {
      case "openCamera":
        this.openCamera(result)
        break;
      default:
        result.notImplemented()
        break;
    }
  }
})

}

onDetachedFromEngine(binding: FlutterPluginBinding): void {

this.channel?.setMethodCallHandler(null);

}

// native api
openCamera (result: MethodResult) {

// 回传数据给 Flutter
result.success('http://test.png')

}
}
注册插件

entryAbility.ets

// Initial FlutterBoost
const optionsBuilder: FlutterBoostSetupOptionsBuilder = new FlutterBoostSetupOptionsBuilder()
FlutterBoost.getInstance().setup(this, this.context, (engine) => {
GeneratedPluginRegistrant.registerWith(engine)
// 打开相机
engine.getPlugins()?.add(new NativePlugin())
}, optionsBuilder.build())
总结
使用 flutter_boost 开发 Flutter混合项目，在鸿蒙这边和混合 Web 组件进行混合开发很相似，搞定Flutter页面栈+鸿蒙页面栈跳转，搞定数据通信和原生调用，基本可以满足一般的开发，以上这里仅供参考哈~