在main中发送一个参数，并在widget的构建中使用它(Flutter dart)

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp("Hello World"));
}

class MyApp extends StatelessWidget {
  final String message;

  MyApp(this.message);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Parameter Example'),
        ),
        body: Center(
          child: Text(message),
        ),
      ),
    );
  }
}