flutter CircularProgressIndicator的使用

import 'package:flutter/material.dart';

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body:
        CustomScrollView(
          slivers: [
            SliverList(
              delegate: SliverChildBuilderDelegate(
                    (context, index) {
                  if (index == 5) {
                    return Center(child: CircularProgressIndicator());
                  }
                  return ListTile(title: Text('Item $index'));
                },
                childCount: 6,
              ),
            ),
          ],
        )
      ),
    );
  }
}