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

bash 复制代码

flutter create -t module --org xyz.zhousg demo_fluter

打包 Fluter 项目

bash 复制代码

flutter build har --debug

Fluter 引入 flutter_boost

安装依赖

diff 复制代码

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

dart 复制代码

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

text 复制代码

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

b. 在鸿蒙项目中，引入依赖

oh-package.json5

json5 复制代码

"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

TS 复制代码

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

ts 复制代码

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

ts 复制代码

// 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

dart 复制代码

  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

ts 复制代码

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

dart 复制代码

final _platform = const MethodChannel('xyz.zhousg.interview_success_project');

dart 复制代码

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

ts 复制代码

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

ts 复制代码

// 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~