Argthtjtr

I am using this package.
The package is a widget provided to the flutter scroll component drop-down refresh and pull up load.support android and ios
The package url is https://pub.dartlang.org/packages/pull_to_refresh
But this package has a bug !

import 'dart:async';



import 'package:flutter/material.dart';

import 'package:pull_to_refresh/pull_to_refresh.dart';



class Example1 extends StatefulWidget {

  @override

  _Example1State createState() => new _Example1State();

}



class _Example1State extends State<Example1> {

//  RefreshMode  refreshing = RefreshMode.idle;

//  LoadMode loading = LoadMode.idle;

  RefreshController _refreshController;

  List<Widget> data = ;

  void _getDatas() {

    for (int i = 0; i < 14; i++) {

      data.add(new Card(

        margin:

            new EdgeInsets.only(left: 10.0, right: 10.0, top: 5.0, bottom: 5.0),

        child: new Center(

          child: new Text('Data $i'),

        ),

      ));

    }

  }



  void enterRefresh() {

    _refreshController.requestRefresh(true);

  }



  void _onOffsetCallback(bool isUp, double offset) {

    // if you want change some widgets state ,you should rewrite the callback

  }



  @override

  void initState() {

    // TODO: implement initState

    _getDatas();

    _refreshController = new RefreshController();

    super.initState();

  }



  Widget _headerCreate(BuildContext context, int mode) {

    return new ClassicIndicator(

      mode: mode,

      refreshingText: "",

      idleIcon: new Container(),

      idleText: "Load more...",

    );

  }



//  Widget _footerCreate(BuildContext context,int mode){

//    return new ClassicIndicator(mode: mode);

//  }



  @override

  Widget build(BuildContext context) {

    return new Container(

        child: new SmartRefresher(

            enablePullDown: true,

            enablePullUp: true,

            controller: _refreshController,

            onRefresh: (up) {

              if (up)

                new Future.delayed(const Duration(milliseconds: 2009))

                    .then((val) {

                  data.add(new Card(

                    margin: new EdgeInsets.only(

                        left: 10.0, right: 10.0, top: 5.0, bottom: 5.0),

                    child: new Center(

                      child: new Text('Data '),

                    ),

                  ));



                  _refreshController.scrollTo(_refreshController.scrollController.offset+100.0);

                  _refreshController.sendBack(true, RefreshStatus.idle);

                  setState(() {});

//                refresher.sendStatus(RefreshStatus.completed);

                });

              else {

                new Future.delayed(const Duration(milliseconds: 2009))

                    .then((val) {

                  data.add(new Card(

                    margin: new EdgeInsets.only(

                        left: 10.0, right: 10.0, top: 5.0, bottom: 5.0),

                    child: new Center(

                      child: new Text('Data '),

                    ),

                  ));

                  setState(() {});

                  _refreshController.sendBack(false, RefreshStatus.idle);

                });

              }

            },

            onOffsetChange: _onOffsetCallback,

            child: new ListView.builder(

              reverse: true,

              itemExtent: 100.0,

              itemCount: data.length,

              itemBuilder: (context, index) => new Item(),

            )));

  }

}



class Item extends StatefulWidget {

  @override

  _ItemState createState() => new _ItemState();

}



class _ItemState extends State<Item> {

  @override

  Widget build(BuildContext context) {

    return new Card(

      margin:

          new EdgeInsets.only(left: 10.0, right: 10.0, top: 5.0, bottom: 5.0),

      child: new Center(

        child: new Text('Data'),

      ),

    );

  }



  @override

  void dispose() {

    // TODO: implement dispose

    print("销毁");

    super.dispose();

  }

}

When I tap the status bar，can't scroll to the top!
I tried to debug this package, I found that in line 344 of the smart_refresher.dart file, just comment the controller property and scroll back to the top, like this

But the pull-down refresh action will give an error.

flutter: ══╡ EXCEPTION CAUGHT BY ANIMATION LIBRARY ╞═════════════════════════════════════════════════════════

flutter: The following assertion was thrown while notifying listeners for AnimationController:

flutter: ScrollController not attached to any scroll views.

flutter: 'package:flutter/src/widgets/scroll_controller.dart': Failed assertion: line 110 pos 12:

flutter: '_positions.isNotEmpty'

flutter:

flutter: Either the assertion indicates an error in the framework itself, or we should provide substantially

flutter: more information in this error message to help you determine and fix the underlying cause.

flutter: In either case, please report this assertion by filing a bug on GitHub:

flutter:   https://github.com/flutter/flutter/issues/new?template=BUG.md

flutter:

flutter: When the exception was thrown, this was the stack:

flutter: #2      ScrollController.position (package:flutter/src/widgets/scroll_controller.dart:110:12)

flutter: #3      ScrollController.offset (package:flutter/src/widgets/scroll_controller.dart:118:24)

flutter: #4      _SmartRefresherState._buildWrapperByConfig.<anonymous closure> (package:pull_to_refresh/src/smart_refresher.dart:291:42)

flutter: #5      RefreshWrapperState._handleOffsetCallBack (package:pull_to_refresh/src/internals/indicator_wrap.dart:163:14)

flutter: #6      _AnimationController&Animation&AnimationEagerListenerMixin&AnimationLocalListenersMixin.notifyListeners (package:flutter/src/animation/listener_helpers.dart:124:19)

flutter: #7      AnimationController.value= (package:flutter/src/animation/animation_controller.dart:351:5)

flutter: #8      RefreshWrapperState._handleModeChange (package:pull_to_refresh/src/internals/indicator_wrap.dart:171:25)

flutter: #9      ChangeNotifier.notifyListeners (package:flutter/src/foundation/change_notifier.dart:208:21)

flutter: #10     ValueNotifier.value= (package:flutter/src/foundation/change_notifier.dart:264:5)

flutter: #11     Wrapper.mode= (package:pull_to_refresh/src/internals/indicator_wrap.dart:31:43)

flutter: #12     RefreshWrapperState.onDragEnd (package:pull_to_refresh/src/internals/indicator_wrap.dart:157:14)

flutter: #13     _SmartRefresherState._handleScrollEnd (package:pull_to_refresh/src/smart_refresher.dart:120:40)

flutter: #14     _SmartRefresherState._dispatchScrollEvent (package:pull_to_refresh/src/smart_refresher.dart:133:16)

flutter: #15     NotificationListener._dispatch (package:flutter/src/widgets/notification_listener.dart:125:27)

flutter: #16     Notification.visitAncestor (package:flutter/src/widgets/notification_listener.dart:45:20)

flutter: #17     _ScrollNotification&LayoutChangedNotification&ViewportNotificationMixin.visitAncestor (package:flutter/src/widgets/scroll_notification.dart:31:18)

flutter: #18     Element.visitAncestorElements (package:flutter/src/widgets/framework.dart:3344:39)

flutter: #19     Notification.dispatch (package:flutter/src/widgets/notification_listener.dart:59:12)

flutter: #20     ScrollActivity.dispatchScrollUpdateNotification (package:flutter/src/widgets/scroll_activity.dart:96:92)

flutter: #21     ScrollPosition.didUpdateScrollPositionBy (package:flutter/src/widgets/scroll_position.dart:654:14)

flutter: #22     ScrollPosition.setPixels (package:flutter/src/widgets/scroll_position.dart:219:9)

flutter: #23     ScrollPositionWithSingleContext.setPixels (package:flutter/src/widgets/scroll_position_with_single_context.dart:84:18)

flutter: #24     BallisticScrollActivity.applyMoveTo (package:flutter/src/widgets/scroll_activity.dart:547:21)

flutter: #25     BallisticScrollActivity._tick (package:flutter/src/widgets/scroll_activity.dart:534:10)

flutter: #26     _AnimationController&Animation&AnimationEagerListenerMixin&AnimationLocalListenersMixin.notifyListeners (package:flutter/src/animation/listener_helpers.dart:124:19)

flutter: #27     AnimationController._tick (package:flutter/src/animation/animation_controller.dart:697:5)

flutter: #28     Ticker._tick (package:flutter/src/scheduler/ticker.dart:228:5)

flutter: #29     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15)

flutter: #30     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleBeginFrame.<anonymous closure> (package:flutter/src/scheduler/binding.dart:906:11)

flutter: #31     __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.forEach (dart:collection/runtime/libcompact_hash.dart:370:8)

flutter: #32     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleBeginFrame (package:flutter/src/scheduler/binding.dart:904:17)

flutter: #33     _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleBeginFrame (package:flutter/src/scheduler/binding.dart:834:5)

flutter: #34     _invoke1 (dart:ui/hooks.dart:168:13)

flutter: #35     _beginFrame (dart:ui/hooks.dart:138:3)

flutter: (elided 2 frames from class _AssertionError)

flutter:

flutter: The AnimationController notifying listeners was:

flutter:   AnimationController#96484(⏭ 1.000; paused)

flutter: ════════════════════════════════════════════════════════════════════════════════════════════════════

flutter: Another exception was thrown: ScrollController not attached to any scroll views.

[VERBOSE-2:shell.cc(184)] Dart Error: Unhandled exception:

'package:flutter/src/widgets/scroll_controller.dart': Failed assertion: line 110 pos 12: '_positions.isNotEmpty': ScrollController not attached to any scroll views.

#0      _AssertionError._doThrowNew (dart:core/runtime/liberrors_patch.dart:40:39)

#1      _AssertionError._throwNew (dart:core/runtime/liberrors_patch.dart:36:5)

#2      ScrollController.position (package:flutter/src/widgets/scroll_controller.dart:110:12)

#3      ScrollController.offset (package:flutter/src/widgets/scroll_controller.dart:118:24)

#4      _Example1State.build.<anonymous closure>.<anonymous closure> (package:example/ui/Example1.dart:76:83)

#5      _RootZone.runUnary (dart:async/zone.dart:1379:54)

#6      _FutureListener.handleValue (dart:async/future_impl.dart:129:18)

#7      Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:642:45)

#8      Future._propagateToListeners (dart:async/future_impl.dart:671:32)

#9      Future._complete (dart:as<…>

Relevant doctor info:

[✓] Flutter (Channel dev, v0.11.6, on Mac OS X 10.13.6 17G65, locale

zh-Hans-CN) [✓] Android toolchain - develop for Android devices

(Android SDK 28.0.3) [✓] iOS toolchain - develop for iOS devices

(Xcode 10.1) [✓] Android Studio (version 3.2)

[✓] VS Code (version> 1.29.1)

[✓] Connected device (1 available)

Please help me solve this bug, thank you.