Flutter 和 OpenHarmony 通信 pigeon 库的具体接入和用法

dev_dependencies: pigeon:   git:     url: "https://gitee.com/openharmony-sig/flutter_packages.git"     path: "packages/pigeon"

import 'package:pigeon/pigeon.dart';
// #docregion config@ConfigurePigeon(PigeonOptions(  dartOut: 'lib/src/messages.g.dart',  dartOptions: DartOptions(),  cppOptions: CppOptions(namespace: 'pigeon_example'),  cppHeaderOut: 'windows/runner/messages.g.h',  cppSourceOut: 'windows/runner/messages.g.cpp',  kotlinOut:      'android/app/src/main/kotlin/dev/flutter/pigeon_example_app/Messages.g.kt',  kotlinOptions: KotlinOptions(),  javaOut: 'android/app/src/main/java/io/flutter/plugins/Messages.java',  javaOptions: JavaOptions(),  swiftOut: 'ios/Runner/Messages.g.swift',  swiftOptions: SwiftOptions(),  objcHeaderOut: 'macos/Runner/messages.g.h',  objcSourceOut: 'macos/Runner/messages.g.m',  // Set this to a unique prefix for your plugin or application, per Objective-C naming conventions.  objcOptions: ObjcOptions(prefix: 'PGN'),  copyrightHeader: 'pigeons/copyright.txt',  dartPackageName: 'pigeon_example_package',  arkTSOut: 'ohos/entry/src/main/ets/plugins/Messages.ets',  arkTSOptions: ArkTSOptions(),))// #enddocregion config
// This file and ./messages_test.dart must be identical below this line.
// #docregion host-definitionsenum Code { one, two }
class MessageData {  MessageData({required this.code, required this.data});  String? name;  String? description;  Code code;  Map<String?, String?> data;}
@HostApi()abstract class ExampleHostApi {  String getHostLanguage();
  // These annotations create more idiomatic naming of methods in Objc and Swift.  @ObjCSelector('addNumber:toNumber:')  @SwiftFunction('add(_:to:)')  int add(int a, int b);
  @async  bool sendMessage(MessageData message);}// #enddocregion host-definitions
// #docregion flutter-definitions@FlutterApi()abstract class MessageFlutterApi {  String flutterMethod(String? aString);}// #enddo

import {  FlutterPlugin,  FlutterPluginBinding} from '@ohos/flutter_ohos/src/main/ets/embedding/engine/plugins/FlutterPlugin';import { ExampleHostApi, MessageData, Result } from './Messages';
class HostApiImp extends ExampleHostApi {  getHostLanguage(): string {    return 'ArkTS';  }
  add(a: number, b: number): number {    return a + b;  }
  sendMessage(message: MessageData, result: Result<boolean>) {    console.log("收到消息：" + message.getName());  }}
export default class MessagePlugin implements FlutterPlugin {
  constructor() {  }
  getUniqueClassName(): string {    return 'MessagePlugin';  }
  onAttachedToEngine(binding: FlutterPluginBinding) {    ExampleHostApi.setup(binding.getBinaryMessenger(), new HostApiImp());  }
  onDetachedFromEngine(binding: FlutterPluginBinding) {    //ExampleHostApi.setup(binding.getBinaryMessenger(), null);  }}

class _ExampleFlutterApi implements MessageFlutterApi {  @override  String flutterMethod(String? aString) {    return aString ?? '';  }}
class MyHomePage extends StatefulWidget {  const MyHomePage({super.key, required this.title});
  final String title;
  @override  State<MyHomePage> createState() => _MyHomePageState();}
class _MyHomePageState extends State<MyHomePage> {  final ExampleHostApi _hostApi = ExampleHostApi();  String? _hostCallResult;
  // #docregion main-dart  final ExampleHostApi _api = ExampleHostApi();
  /// Calls host method `add` with provided arguments.  Future<int> add(int a, int b) async {    try {      return await _api.add(a, b);    } catch (e) {      // handle error.      return 0;    }  }
  /// Sends message through host api using `MessageData` class  /// and api `sendMessage` method.  Future<bool> sendMessage(String messageText) {    final MessageData message = MessageData(      code: Code.one,      data: <String?, String?>{'header': 'this is a header'},      description: 'uri text',    );    try {      return _api.sendMessage(message);    } catch (e) {      // handle error.      return Future<bool>(() => true);    }  }  // #enddocregion main-dart
  @override  void initState() {    super.initState();    _hostApi.getHostLanguage().then((String response) {      setState(() {        _hostCallResult = 'Hello from $response!';      });    }).onError<PlatformException>((PlatformException error, StackTrace _) {      setState(() {        _hostCallResult = 'Failed to get host language: ${error.message}';      });    });  }
  @override  Widget build(BuildContext context) {    return Scaffold(      appBar: AppBar(        backgroundColor: Theme.of(context).colorScheme.inversePrimary,        title: Text(widget.title),      ),      body: Center(        child: Column(          mainAxisAlignment: MainAxisAlignment.center,          children: <Widget>[            Text(              _hostCallResult ?? 'Waiting for host language...',            ),            if (_hostCallResult == null) const CircularProgressIndicator(),          ],        ),      ),    );  }}