您需要在Scaffold小部件的body参数中使用小部件Column，以便能够在屏幕的列视图中添加多个小部件。
您可以在zaap.run link中找到一个完整的工作示例。
您也可以在这里找到没有任何预览的代码：

import 'package:flutter/material.dart';

void main() {
  // debugPaintSizeEnabled = true;
  runApp(const HomePage());
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Medicine Reminder App'),
        ),
        body: Column(children: [
          Stack(
            children: [
              Image.network(
                'https://i.imgur.com/9ZOaH1m.jpeg',
                width: 600,
                height: 200,
                fit: BoxFit.cover,
              ),
            ],
          ),
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceAround,
            children: [
              TextButton(
                style: ButtonStyle(
                    backgroundColor: MaterialStateProperty.all(Colors.black)),
                onPressed: () {},
                child: Text("Button1"),
              ),
              TextButton(
                style: ButtonStyle(
                    backgroundColor: MaterialStateProperty.all(Colors.black)),
                onPressed: () {},
                child: Text("Button2"),
              ),
              TextButton(
                style: ButtonStyle(
                    backgroundColor: MaterialStateProperty.all(Colors.black)),
                onPressed: () {},
                child: Text("Button3"),
              ),
            ],
          )
        ]),
      ),
    );
  }
}

只需将Stack更改为Column或Listiw

body: Column(
 children: [
  Image.asset(
    'images/MenuImg.jpg',
    width: 600,
    height: 200,
    fit: BoxFit.cover,
  ),
  /// your button is here:
  Row(
  children:[
  ElevetedButton(),// btn 1
  ElevetedButton(),// btn 2
  ... 
 ],
),

您可以使用Column Package 图像小部件，以设置垂直排序的小部件，我这样做是为了使用MainAxisAlignment.spaceBetween显示按钮，以分隔它们
试试这个：

import 'package:flutter/material.dart';
import 'package:get/get_core/src/get_main.dart';
import 'package:get/get_navigation/get_navigation.dart';
import 'Reminder/ui/home_reminder.dart';
import 'Reminder/ui/widgets/button.dart';

void main() {
  // debugPaintSizeEnabled = true;
  runApp(const HomePage());
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Medicine Reminder App'),
        ),
        body: Column(
          children: [
            Stack(
              children: [
                Image.asset(
                  'images/MenuImg.jpg',
                  width: 600,
                  height: 200,
                  fit: BoxFit.cover,
                ),
              ],
            ),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                ElevatedButton(
                  child: Text('btn 1'),
                  onPressed: () {},
                ),
                ElevatedButton(
                  child: Text('btn 2'),
                  onPressed: () {},
                ),
                ElevatedButton(
                  child: Text('btn 3'),
                  onPressed: () {},
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

请尝试以下代码：

import 'package:flutter/material.dart';
import 'package:get/get_core/src/get_main.dart';
import 'package:get/get_navigation/get_navigation.dart';
import 'Reminder/ui/home_reminder.dart';
import 'Reminder/ui/widgets/button.dart';

void main() {
  // debugPaintSizeEnabled = true;
  runApp(const HomePage());
}

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Medicine Reminder App'),
        ),
        body: Column(
          children: [
            Stack(
              children: [
                Image.asset(
                  'images/MenuImg.jpg',
                  width: 600,
                  height: 200,
                  fit: BoxFit.cover,
                ),
              ],
            ),
            const SizedBox(height: 10.0),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                ElevatedButton(
                  child: const Text('Button 1'),
                  onPressed: () {
                    Navigator.push(
                      context,
                      MaterialPageRoute(
                        builder: (context) => const Scaffold(
                          body: body,
                        ),
                      ),
                    );
                  },
                ),
                ElevatedButton(
                  child: const Text('Button 2'),
                  onPressed: () {
                    Navigator.push(
                      context,
                      MaterialPageRoute(
                        builder: (context) => const Scaffold(
                          body: body,
                        ),
                      ),
                    );
                  },
                ),
                ElevatedButton(
                  child: const Text('Button 3'),
                  onPressed: () {
                    Navigator.push(
                      context,
                      MaterialPageRoute(
                        builder: (context) => const Scaffold(
                          body: body,
                        ),
                      ),
                    );
                  },
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}