第一次加载数据存在问题，没有更新记录和优化MVC结构中的代码，并且没有任何使用包。
完整代码在此链接https://github.com/RajTechnologiesPvtLtd/flutter-moonlight/blob/master/lib/views/example_mvc/LoadMoreViewMVC.dart
config

class ApiEndpoint {
  static const loadMoreUrl = 'https://jsonplaceholder.typicode.com/posts';
}

字符串
LoadMoreModelMVC（模型）

import 'package:http/http.dart' as http;
import 'dart:convert';
import 'package:flutter/material.dart';

import '../config/config.dart';

class LoadMoreModelMVC {
  int _page = 0;
  final int _limit = 20;
  bool _hasNextPage = true;
  bool _isFirstLoadRunning = false;
  bool _isLoadMoreRunning = false;
  List _records = [];
  final _baseUrl = ApiEndpoint.loadMoreUrl;

  late ScrollController _controller;
  // Getters
  List get records => _records;
  bool get hasNextPage => _hasNextPage;
  
  Future<void> firstLoad() async {
    _isFirstLoadRunning = true;
    try {
      final res =
          await http.get(Uri.parse("$_baseUrl?_page=$_page&_limit=$_limit"));
      _records = json.decode(res.body);      
    } catch (err) {
      print('Something went wrong');
    }
    _isFirstLoadRunning = false;
  }

  Future<void> loadMore() async {
    if (_hasNextPage == true &&
        _isFirstLoadRunning == false &&
        _isLoadMoreRunning == false &&
        _controller.position.extentAfter < 300) {
      _isLoadMoreRunning = true;
      _page += 1;
      try {
        final res =
            await http.get(Uri.parse("$_baseUrl?_page=$_page&_limit=$_limit"));
        final List fetchedRecords = json.decode(res.body);
        if (fetchedRecords.isNotEmpty) {
          _records.addAll(fetchedRecords);
        } else {
          _hasNextPage = false;
        }
      } catch (err) {
        print('Something went wrong!');
      }

      _isLoadMoreRunning = false;
    }
  }

  void initController() {
    _controller = ScrollController();
  }

  void disposeController() {
    _controller.dispose();
  }

  ScrollController getController() {
    return _controller;
  }

  // List getRecords() {
  //   return _records;
  // }

  // bool getIsFirstLoadRunning() {
  //   return _isFirstLoadRunning;
  // }

  // bool getIsLoadMoreRunning() {
  //   return _isLoadMoreRunning;
  // }

  // bool getHasNextPage() {
  //   return _hasNextPage;
  // }

  Future<void> refresh() async {
    _page = 0;
    _hasNextPage = true;
    _records = [];
    await firstLoad();
  }
}

型
LoadMoreControllerMVC（控制器）

import '../models/LoadMoreModelMVC.dart';

class LoadMoreControllerMVC {
  final LoadMoreModelMVC model = LoadMoreModelMVC();

  Future<void> fetchFirstRecords() async {
    await model.firstLoad();
  }

  Future<void> fetchMoreRecords() async {
    await model.loadMore();
  }
}

型
LoadMoreViewMVC（视图）

import 'package:flutter/material.dart';
import '../../controllers/controllers.dart';
import '../../widgets/widgets.dart';

class LoadMoreViewMVC extends StatefulWidget {
  const LoadMoreViewMVC({Key? key}) : super(key: key);

  @override
  State<LoadMoreViewMVC> createState() => _LoadMoreViewMVCState();
}

class _LoadMoreViewMVCState extends State<LoadMoreViewMVC> {
  final LoadMoreControllerMVC controller = LoadMoreControllerMVC();
  final ScrollController _scrollController = ScrollController();

  @override
  void initState() {
    super.initState();
    controller.fetchFirstRecords();
    _scrollController.addListener(_loadMore);
  }

  @override
  void dispose() {
    _scrollController.removeListener(_loadMore);
    super.dispose();
  }

  void _loadMore() {
    final double scrollExtent = _scrollController.position.maxScrollExtent;
    final double currentPosition = _scrollController.position.pixels;
    final double delta = scrollExtent - currentPosition;
    if (delta < 200 && controller.model.hasNextPage) {
      controller.fetchMoreRecords();
    }
  }

  Widget _buildList() {
    if (controller.model.records.isEmpty) {
      return const Center(child: CircularProgressIndicator());
    } else {
      return ListView.builder(
        controller: _scrollController,
        itemCount: controller.model.records.length +
            (controller.model.hasNextPage ? 1 : 0),
        itemBuilder: (_, index) {
          if (index == controller.model.records.length) {
            return const Center(child: CircularProgressIndicator());
          } else {
            final record = controller.model.records[index];
            return Card(
              margin: const EdgeInsets.symmetric(vertical: 8, horizontal: 10),
              child: ListTile(
                title: Text(record['title']),
              ),
            );
          }
        },
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      drawer: const MoonLightDrawer("Load More MVC"),
      appBar: const Navbar(title: "Load More MVC"),
      body: _buildList(),
    );
  }
}

型