Flutter 上滑加载以及下拉刷新

实现下拉刷新

• flutter中，已经给出了实现，咱们只需要给出回调即可。
• 很多解释都在注释中，请不要忽略。
• 如果你想要直接看到全部代码，请拉到最后。

import 'dart:async';

import 'package:dio/dio.dart';
import 'package:flutter/material.dart';
import 'package:flutter_demo/base/view.dart';
import 'package:flutter_demo/common/my_flutter_toast/MyToast.dart';
import 'package:flutter_demo/common/my_flutter_toast/ToastType.dart';
import 'package:flutter_demo/view/news/NewsItem.dart';
import 'Model.dart';

class NewsPage extends StatefulWidget {
  @override
  _NewsPageState createState() => _NewsPageState();
}

class _NewsPageState extends State<NewsPage> {
  List _goodsList = [];
  int _currentPage = 1;
  int _pageSize = 15;
  //数据是否全部加载完毕
  bool _isOver = false;

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    this._initData();
  }

  @override
  void dispose() {
    // TODO: implement dispose
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
    // 封装的工具方法，如果使用请修改为正常写法
      appBar: getAppBar('News Center'),
      body: RefreshIndicator(
          onRefresh: () async {
          // 这里写下拉刷新后执行的代码
            print(1);
          },
          child: ListView.builder(
            itemBuilder: _builder,
            itemCount: this._goodsList.length,
          )),
    );
  }

  Widget _builder(BuildContext context, int index) {
    return NewsItem(Goods(
      this._goodsList[index]['title'],
      this._goodsList[inde