​​​​​​

• 创建 package

flutter create --template=package mypackage

package代码如下：

        创建hello_world.dart        

///HelloWorld返回hello world 拼接param
class HelloWorld {
  String helloWorld(String param) => "hello world ${param}";
}

        导出hello_world.dart

library mypackage;

export 'src/hello_world.dart';

• 创建flutter项目

flutter create myflutter

• myflutter pubspec.yaml中引入myPackage

dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: ^1.0.2
  mypackage:
    path: /Users/administrator/Desktop/workspace/mypackage

• myflutter中调用

import 'package:flutter/material.dart';
import 'package:mypackage/mypackage.dart';

void main() {
  runApp(const MyApp());
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

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

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  String helloWorld ="";

  @override
  void initState() {
    super.initState();
    helloWorld = HelloWorld().helloWorld("我是拼接的字符串!");
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("你好世界"),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text('${helloWorld}',style: TextStyle(fontWeight: FontWeight.bold,fontSize: 26),)
          ],
        ),
      ),
    );
  }
}

• 效果展示