title: An error happened while using swipper in flutter
body: <p>i use SliverList to hide the the swiper but it give me errors about the swiper's controller (I think ) that state Is not saved or something help me fix it and thanks a lot </p>
  
  <p>the UI code </p>
  
  <pre><code>    import 'package:flutter/material.dart';
  import 'package:flutter_swiper/flutter_swiper.dart';
  import 'package:medixa_app/Routes/CategoryRoute.dart';
  
  class HomeTab extends StatefulWidget {
    @override
    _HomeTabState createState() =&gt; _HomeTabState();
  }
  
  class _HomeTabState extends State&lt;HomeTab&gt; {
    var names = [
      'INFO',
      'ABOUT',
      'EVO',
      'CONTACT US',
    ];
  
    var links = [
      'https://images.pexels.com/photos/1282308/pexels-photo-1282308.jpeg?auto=compress&amp;cs=tinysrgb&amp;h=650&amp;w=940',
      'https://images.pexels.com/photos/40568/medical-appointment-doctor-healthcare-40568.jpeg?auto=compress&amp;cs=tinysrgb&amp;h=650&amp;w=940',
      'https://images.pexels.com/photos/935869/pexels-photo-935869.jpeg?auto=compress&amp;cs=tinysrgb&amp;h=650&amp;w=940',
    ];
  
    var swiperController;
  
    List&lt;StackFit&gt; stackList = [StackFit.expand, StackFit.loose];
  
    @override
    void initState() {
      super.initState();
      swiperController = SwiperControl(
        iconPrevious: null,
        iconNext: null,
      );
    }
  
    @override
    Widget build(BuildContext context) {
      return Material(
        child: Container(
          child: CustomScrollView(
            slivers: &lt;Widget&gt;[
              SliverList(
  
                delegate: SliverChildListDelegate(
                  &lt;Widget&gt;[
                    Container(
                      height: 50.0,
                      child: ListView.builder(
                        scrollDirection: Axis.horizontal,
                        itemCount: names.length,
                        itemBuilder: (context, i) =&gt; new MenuItem(names[i], i),
                      ),
                    ),
                    new Container(
                      height: 150.0,
                      child: Swiper(
                        loop: false,
                        autoplay: true,
                        itemBuilder: (context, i) {
                          return Stack(
                            alignment: AlignmentDirectional.bottomStart,
                            fit: StackFit.expand,
                            children: &lt;Widget&gt;[
                              Image.network(
                                links[i],
                                fit: BoxFit.cover,
                              ),
                              Container(
                                alignment: AlignmentDirectional.bottomStart,
                                child: Container(
                                  constraints:
                                      BoxConstraints(minWidth: double.maxFinite),
                                  padding: EdgeInsets.symmetric(
                                      vertical: 8.0, horizontal: 16.0),
                                  color: Colors.black54,
                                  child: Text(
                                    'Descreption: ${i}',
                                    style: TextStyle(
                                      color: Colors.white,
                                    ),
                                    textAlign: TextAlign.justify,
                                  ),
                                ),
                              )
                            ],
                          );
                        },
                        itemCount: links.length,
                        pagination: new SwiperPagination(),
                        control: swiperController,
                      ),
                    ),
                  ],
                  addAutomaticKeepAlives: true,
                  addRepaintBoundaries: false
                ),
              ),
              SliverList(
                delegate: SliverChildBuilderDelegate((context, i) {
                  return new Container(
                    height: 80.0,
                    child: Padding(
                      padding: const EdgeInsets.symmetric(horizontal: 16.0),
                      child: Row(
                        children: &lt;Widget&gt;[
                          Icon(
                            Icons.account_circle,
                            color: Colors.deepPurple[((i + 1) % 10) * 100],
                            size: 48.0,
                          ),
                          Padding(
                            padding: const EdgeInsets.symmetric(horizontal: 8.0),
                            child: Center(
                              child: Text('Title: ${i + 1}'),
                            ),
                          )
                        ],
                      ),
                    ),
                  );
                }, childCount: 20),
              )
            ],
          ),
        ),
      );
    }
  }
  
  class MenuItem extends StatelessWidget {
    final String title;
    final int id;
  
    MenuItem(this.title, this.id);
  
    @override
    Widget build(BuildContext context) {
      return Material(
        child: Card(
          margin: EdgeInsets.symmetric(
            vertical: 8.0,
            horizontal: 8.0,
          ),
          child: InkWell(
            onTap: () {
              Navigator.push(
                  context,
                  new MaterialPageRoute(
                      builder: (context) =&gt; new CategoryRoute(title, id)));
            },
            child: Center(
              child: Padding(
                padding: const EdgeInsets.symmetric(horizontal: 16.0),
                child: Text(title),
              ),
            ),
          ),
        ),
      );
    }
  }
  </code></pre>
  
  <p>the error </p>
  
  <blockquote>
    <p>I/flutter ( 2601): ══╡ EXCEPTION CAUGHT BY FOUNDATION LIBRARY ╞════════════════════════════════════════════════════════
    I/flutter ( 2601): The following assertion was thrown while dispatching notifications for SwiperController:
    I/flutter ( 2601): Looking up a deactivated widget's ancestor is unsafe.
    I/flutter ( 2601): At this point the state of the widget's element tree is no longer stable. To safely refer to a
    I/flutter ( 2601): widget's ancestor in its dispose() method, save a reference to the ancestor by calling
    I/flutter ( 2601): inheritFromWidgetOfExactType() in the widget's didChangeDependencies() method.
    I/flutter ( 2601): When the exception was thrown, this was the stack:
    I/flutter ( 2601): #0      Element._debugCheckStateIsActiveForAncestorLookup. (package:flutter/src/widgets/framework.dart:3233:9)
    I/flutter ( 2601): #1      Element._debugCheckStateIsActiveForAncestorLookup (package:flutter/src/widgets/framework.dart:3242:6)
    I/flutter ( 2601): #2      Element.visitAncestorElements (package:flutter/src/widgets/framework.dart:3329:12)
    I/flutter ( 2601): #3      Notification.dispatch (package:flutter/src/widgets/notification_listener.dart:59:12)
    I/flutter ( 2601): #4      ScrollActivity.dispatchScrollEndNotification (package:flutter/src/widgets/scroll_activity.dart:106:63)
    I/flutter ( 2601): #5      ScrollPosition.didEndScroll (package:flutter/src/widgets/scroll_position.dart:639:14)
    I/flutter ( 2601): #6      ScrollPosition.beginActivity (package:flutter/src/widgets/scroll_position.dart:608:9)
    I/flutter ( 2601): #7      ScrollPositionWithSingleContext.beginActivity (package:flutter/src/widgets/scroll_position_with_single_context.dart:117:11)
    I/flutter ( 2601): #8      ScrollPositionWithSingleContext.goIdle (package:flutter/src/widgets/scroll_position_with_single_context.dart:132:5)
    I/flutter ( 2601): #9      ScrollPositionWithSingleContext.jumpTo (package:flutter/src/widgets/scroll_position_with_single_context.dart:196:5)
    I/flutter ( 2601): #10     ScrollPositionWithSingleContext.animateTo (package:flutter/src/widgets/scroll_position_with_single_context.dart:178:7)
    I/flutter ( 2601): #11     PageController.animateToPage (package:flutter/src/widgets/page_view.dart:119:21)
    I/flutter ( 2601): #12     _TransformerPageViewState.onChangeNotifier (package:transformer_page_view/transformer_page_view.dart:582:12)
    I/flutter ( 2601): #13     ChangeNotifier.notifyListeners (package:flutter/src/foundation/change_notifier.dart:161:21)
    I/flutter ( 2601): #14     IndexController.next (package:transformer_page_view/index_controller.dart:70:5)
    I/flutter ( 2601): #15     _SwiperTimerMixin._onTimer (package:flutter_swiper/src/swiper.dart:370:17)
    I/flutter ( 2601): #16     _Timer._runTimers (dart:isolate/runtime/libtimer_impl.dart:382:19)
    I/flutter ( 2601): #17     _Timer._handleMessage (dart:isolate/runtime/libtimer_impl.dart:416:5)
    I/flutter ( 2601): #18     _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:171:12)
    I/flutter ( 2601): The SwiperController sending notification was:
    I/flutter ( 2601):   Instance of 'SwiperController'</p>
  </blockquote>
  
  <p>the dependcy :  </p>
  
  <blockquote>
    <p>flutter_swiper : ^1.1.4</p>
  </blockquote>
  
  <p>thanks a lot </p>