DraggableScrollableSheet

DraggableScrollableSheet.dart

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

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Draggable-Scrollable'),
        ),
        body: Stack(
          children: <Widget>[
            Container(
            child: SingleChildScrollView(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                children: <Widget>[
                  Container(
                    child: Padding(
                      padding: const EdgeInsets.all(16.0),
                      child: Text(
                        'Draggable-Scrollable Sheet Widget Demo',
                        style:
                            TextStyle(fontSize: 25, fontWeight: FontWeight.w500),
                        textAlign: TextAlign.center,
                      ),
                    ),
                  ),
                  Container(
                    child: Padding(
                      padding: const EdgeInsets.all(16.0),
                      child: Text(
                        'This is demo for draggable scrollable sheet widget. Swipe up the container.',
                        textAlign: TextAlign.center,
                        style: TextStyle(
                          fontSize: 30,
                          fontWeight: FontWeight.w400,
                        ),
                      ),
                    ),
                  ),
                  SizedBox(
                    height: 40.0,
                  ),
                  Container(
                    child: Column(
                      children: <Widget>[
                        Container(
                          child: Text(
                            'Developed by WebToddler. ',
                            style: TextStyle(
                                fontSize: 20, fontWeight: FontWeight.w500),
                          ),
                        ),
                      ],
                    ),
                  ),
                  SizedBox(
                    height: 15.0,
                  ),
                  Container(
                    child: Column(
                      children: <Widget>[
                        Padding(
                          padding: const EdgeInsets.all(16.0),
                          child: Container(
                            child: Text(
                              'Please \nLIKE, SHARE  and \nSubscribe to my YouTube Channel.',
                              style: TextStyle(
                                  fontSize: 20, fontWeight: FontWeight.w500),
                            ),
                          ),
                        ),
                      ],
                    ),
                  ),
                ],
              ),
            ),
          ),
            DraggableScrollableSheet(
              builder: (BuildContext context, ScrollController scrollController){
                return Container(
                  decoration: BoxDecoration(
                    borderRadius: BorderRadius.only(topRight: Radius.circular(30), topLeft: Radius.circular(30.0)),
                    color: Colors.teal[200],

                  ),
                  child: ListView.builder(
                      controller: scrollController,
                      itemCount: 25,
                      itemBuilder: (BuildContext context, int index){
                    return ListTile(title : Text('Item $index'),);
                  }),
                );
              },
            )
        ],),
      ),
    );
  }
}

How to dismiss the DraggableScrollableSheet when it open , tried with DraggableScrollableActuator.reset(context); but in my requirement when DraggableScrollableSheet moves up need apply an opacity so used "NotificationListener".

Please help me below is my code link

https://gist.github.com/rashmisridar/9a3606684fdc79fa98a0dbe8199d9881

DraggableScrollableSheet rebuilds all children every frame when dragged.

Please help! See my post at StackOverflow:
https://stackoverflow.com/questions/64101774/draggablescrollablesheet-rebuilds-all-children-every-frame-when-dragged