#26072 with slivers, renders all slivers

main.dart

import 'dart:math';

import 'package:flutter/material.dart';

const numLists = 250;
const numberOfItemsPerList = 10;

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  List<SliverList> innerLists = [];

  @override
  void initState() {
    super.initState();
    for (int i = 0; i < numLists; i++) {
      final _innerList = <ColorRow>[];
      for (int j = 0; j < numberOfItemsPerList; j++) {
        _innerList.add(ColorRow("List $i - Nested $j"));
      }
      innerLists.add(
        SliverList(
          delegate: SliverChildBuilderDelegate(
            (BuildContext context, int index) => _innerList[index],
            childCount: numberOfItemsPerList,
          ),
        ),
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: CustomScrollView(
        slivers: [...innerLists],
      ),
    );
  }
}

class ColorRow extends StatefulWidget {
  const ColorRow(this.rowId, {Key? key}) : super(key: key);

  final String rowId;

  @override
  State createState() => ColorRowState();
}

class ColorRowState extends State<ColorRow> {
  Color? color;

  @override
  void initState() {
    super.initState();
    color = randomColor();
  }

  @override
  Widget build(BuildContext context) {
    print('Building ColorRowState ${widget.rowId}');
    return Container(
      decoration: BoxDecoration(
        gradient: LinearGradient(
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
          colors: [
            randomColor(),
            randomColor(),
          ],
        ),
      ),
      child: Row(
        children: <Widget>[
          Padding(
            padding: const EdgeInsets.all(8.0),
            child: Container(height: 50, width: 50, color: Colors.white),
          ),
          Flexible(
            child: Column(
              children: const <Widget>[
                Padding(
                  padding: EdgeInsets.all(8),
                  child: Text('I\'m a widget!', style: TextStyle(color: Colors.white)),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

Color randomColor() => Color((Random().nextDouble() * 0xFFFFFF).toInt()).withOpacity(1.0);