H5_Flutter/lib/view/demo2.dart

import 'package:flutter/material.dart';

class Demo2 extends StatefulWidget {
  const Demo2({Key? key}) : super(key: key);

  @override
  State<Demo2> createState() => _Demo2State();
}

class _Demo2State extends State<Demo2> {
  @override
  Widget build(BuildContext context) {
    return Container(
      color: Colors.yellow,
    );
  }
}