1、使用方法 布局

SmartRefresher(
controller: _refreshController,
enablePullDown: true,
enablePullUp: true,
header: HeaderWidget(),
footer: FooterWidget(),
onRefresh: _onRefresh,
onLoading: _onLoad,
child:widget)
2、记得释放
@override
void dispose() {
  // TODO: implement dispose
  _refreshController.dispose();
  super.dispose();
3、初始化
RefreshController _refreshController =
RefreshController(initialRefresh: false);
4、获取数据 以及操作逻辑
void getData() {
  ///获取数据
  Map<String, dynamic> params = {};
  selectCourseResponsitory
      .getHigherUpsListData(courseType, majorId, sMajorId, start, (p0) {
    if (start == 0) {
      _refreshController.refreshCompleted();
      dataSource.clear();
    } else {
      if (p0.isEmpty) {
        _refreshController.loadNoData();
      } else {
        _refreshController.loadComplete();
    start = (start + 1) * 10;
    ///10是limit
    dataSource.addAll(p0);
    setState(() {});
          (p0) => {
      print(p0),
      _refreshController.loadFailed(),
      setState(() {})
5、下拉刷新（修改start 即可 逻辑在第四步）
/// 下拉刷新方法
// ignore: missing_return
Future<dynamic> _onRefresh() {
  start = 0;
  getData();
6、加载逻辑（只调用即可 逻辑在第四步）
///上拉加载
Future<dynamic> _onLoad() {
  getData();
自定义header和footer
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:pull_to_refresh/pull_to_refresh.dart';
//用于下拉刷新 头布局
 class HeaderWidget extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return WaterDropHeader(
       refresh: CircularProgressIndicator(),
       complete: Text("刷新完成"),
       idleIcon: new CircularProgressIndicator(),
       waterDropColor: null,
//用于上拉加载 底部布局
 class FooterWidget extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return CustomFooter(
       builder: (BuildContext context, LoadStatus mode) {
         Widget body;
         if (mode == LoadStatus.idle) {
           body = Text("上拉加载");
         } else if (mode == LoadStatus.loading) {
           body = CupertinoActivityIndicator();
         } else if (mode == LoadStatus.failed) {
           body = Text("加载失败");
         } else if (mode == LoadStatus.canLoading) {
           body = Text("松开加载更多");
         } else if(mode == LoadStatus.noMore){
           body = Text("没有更多数据");
       }else{
           // body = Text("没有更多数据");
           body = Text("");
         return Container(
           height: 55.0,
           child: Center(child: body),