CustomScrollView 设置centerKey后第二次下拉不会刷新

[xiaohucode]

感谢大佬的插件，我有需求需要实现下拉加载上一章数据与上滑加载下一章数据
使用CustomScrollView 嵌套由于设置了centerKey 导致刷新加载一章后无法继续刷新加载

实现代码：

import 'dart:async';

import 'package:easy_refresh/easy_refresh.dart';
import 'package:floor/floor.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';

class CustomScrollDelegate extends SliverChildBuilderDelegate {
  Function(int firstIndex, int lastIndex, double leadingScrollOffset,
      double trailingScrollOffset) scrollCallBack;
  Function(int firstIndex, int lastIndex) layoutFinishCallBack;

  int Function(Key key) findChildIndexCallback;

  CustomScrollDelegate(NullableIndexedWidgetBuilder builder,
      {int itemCount,
      this.scrollCallBack,
      this.findChildIndexCallback,
      this.layoutFinishCallBack})
      : super(builder,
            childCount: itemCount,
            findChildIndexCallback: findChildIndexCallback);
  @override
  void didFinishLayout(int firstIndex, int lastIndex) {
    super.didFinishLayout(firstIndex, lastIndex);
    if (layoutFinishCallBack != null) {
      layoutFinishCallBack(firstIndex, lastIndex);
    }
  }

  @override
  double estimateMaxScrollOffset(int firstIndex, int lastIndex,
      double leadingScrollOffset, double trailingScrollOffset) {
    if (scrollCallBack != null) {
      scrollCallBack(
          firstIndex, lastIndex, leadingScrollOffset, trailingScrollOffset);
    }
    return super.estimateMaxScrollOffset(
        firstIndex, lastIndex, leadingScrollOffset, trailingScrollOffset);
  }
}

class MangaList {
  List<String> urls;
  String name;
  MangaList({List<String> this.urls, String this.name});
}

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

  @override
  State<testListView> createState() => _testListViewState();
}

class _testListViewState extends State<testListView> {
  List<MangaList> list = [
    MangaList(
        name: "章节0",
        urls: List.generate(20, (index) => "item:${index}").toList())
  ];

  List<MangaList> prev_list = [

  ];

  ScrollController _controller = ScrollController();
  StreamController<int> _streamController = StreamController.broadcast();

  final _easyRefreshController = EasyRefreshController(
      controlFinishRefresh: true, controlFinishLoad: true);

  @override
  void dispose() {
    _streamController.close();
    super.dispose();
  }

  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    final centerKey = ValueKey<String>("bottom-sliver-list");

    return Scaffold(
      appBar: AppBar(
        title: Text("view"),
      ),
      body: Stack(
        children: [
          EasyRefresh(
            controller: _easyRefreshController,
            header: CupertinoHeader(),

            // onLoad: () {
            //   _easyRefreshController.finishLoad();
            // },
            onRefresh: () async {
              await Future.delayed(Duration(seconds: 2));
              _easyRefreshController.finishRefresh();
              _easyRefreshController.resetHeader();
              prev_list.add(MangaList(
                  name: "章节${prev_list.length + 1}",
                  urls:
                      List.generate(20, (index) => "item:${index}").toList()));
              setState(() {});
            },
            child: CustomScrollView(
              center: centerKey,
              controller: _controller,
              // reverse: true,
              // shrinkWrap: true,

              cacheExtent: 0.0,
              clipBehavior: Clip.none,
              slivers: [
                SliverList(
                  delegate: CustomScrollDelegate(
                    (ctx, i) {
                      return Column(
                        mainAxisSize: MainAxisSize.min,
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: prev_list[i]
                            .urls
                            .map(
                              (m) => Container(
                                alignment: Alignment.center,
                                decoration: BoxDecoration(
                                  border: Border.all(
                                      color: Colors.black, width: 0.2),
                                  color: Colors.blue,
                                ),
                                width: double.infinity,
                                height: 100,
                                child: Text("${prev_list[i].name} ${m}"),
                              ),
                            )
                            .toList(),
                      );
                    },
                    itemCount: prev_list.length,
                  ),
                ),
                SliverList(
                  key: centerKey,
                  delegate: CustomScrollDelegate(
                    (ctx, i) {
                      return Column(
                        mainAxisSize: MainAxisSize.min,
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: list[i]
                            .urls
                            .map(
                              (m) => Container(
                                alignment: Alignment.center,
                                decoration: BoxDecoration(
                                  border: Border.all(
                                      color: Colors.black, width: 0.2),
                                  color: Colors.blue,
                                ),
                                width: double.infinity,
                                height: 100,
                                child: Text("${list[i].name} ${m}"),
                              ),
                            )
                            .toList(),
                      );
                    },
                    itemCount: list.length,
                  ),
                ),
              ],
            ),
          ),

          Positioned(
            bottom: 200,
            right: 10,
            child: Container(
              height: 50,
              width: 50,
              child: StreamBuilder<int>(
                stream: _streamController.stream,
                initialData: 0,
                builder: (context, snapshot) {
                  return TextButton(
                    onPressed: () {},
                    child: Text("${snapshot.data}"),
                  );
                },
              ),
              decoration: BoxDecoration(
                color: Colors.black,
                borderRadius: BorderRadius.all(
                  Radius.circular(50),
                ),
              ),
            ),
          ),
          Positioned(
            bottom: 10,
            right: 10,
            child: Container(
              height: 50,
              width: 50,
              child: TextButton(
                onPressed: () {
                  final mangaList = MangaList(
                      name: "章节${list.length + 1}",
                      urls: List.generate(20, (index) => "item:${100 + index}")
                          .toList());
                  list.insert(list.length, mangaList);
                  setState(() {});
                },
                child: Text("加入"),
              ),
              decoration: BoxDecoration(
                color: Colors.black,
                borderRadius: BorderRadius.all(
                  Radius.circular(50),
                ),
              ),
            ),
          ),
          Positioned(
            bottom: 100,
            right: 10,
            child: Container(
              height: 50,
              width: 50,
              child: TextButton(
                onPressed: () {
                  list.clear();
                  list.add(MangaList(
                      name: "章节1",
                      urls: List.generate(20, (index) => "item:${index}")
                          .toList()));
                  setState(() {});
                },
                child: Text("重置"),
              ),
              decoration: BoxDecoration(
                color: Colors.black,
                borderRadius: BorderRadius.all(
                  Radius.circular(50),
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }
}

[xuelongqy]

目前还不支持center，这个还得研究一下。有兴趣可以加群一起讨论

[xuelongqy]

v3.0.4已修复