flutter bottom sheet

main.dart

import 'package:flutter/material.dart';

void main() {
  runApp(
    MaterialApp(
      home: Scaffold(
        body: Builder(
          builder: (BuildContext context) {
            final size = MediaQuery.of(context).size;
            return Stack(
              children: [
                Image.network(
                  'https://source.unsplash.com/random',
                  width: size.width,
                  height: size.height,
                  fit: BoxFit.cover,
                ),
                Center(
                  child: ElevatedButton(
                    child: const Text('showBottomSheet'),
                    onPressed: () {
                      Scaffold.of(context).showBottomSheet<void>(
                        (_) => Container(
                          margin: const EdgeInsets.all(20),
                          height: size.height * 0.4,
                          width: size.width,
                          decoration: const BoxDecoration(
                            borderRadius: BorderRadius.all(Radius.circular(32)),
                            color: Colors.white,
                          ),
                          child: const Center(child: Text("Hi modal sheet")),
                        ),
                        backgroundColor: Colors.transparent,
                      );
                    },
                  ),
                ),
              ],
            );
          },
        ),
      ),
    ),
  );
}