多个页面都使用了swiper，来回切换页面导致的问题

[shiyu1991]

Unhandled Exception: Looking up a deactivated widget's ancestor is unsafe.
At this point the state of the widget's element tree is no longer stable.
To safely refer to a widget's ancestor in its dispose() method, save a reference to the ancestor by calling dependOnInheritedWidgetOfExactType() in the widget's didChangeDependencies() method.
#0 Element._debugCheckStateIsActiveForAncestorLookup. (package:flutter/src/widgets/framework.dart:4558:9)
#1 Element._debugCheckStateIsActiveForAncestorLookup (package:flutter/src/widgets/framework.dart:4572:6)
#2 Element.getElementForInheritedWidgetOfExactType (package:flutter/src/widgets/framework.dart:4607:12)
#3 Element.getInheritedWidgetOfExactType (package:flutter/src/widgets/framework.dart:4602:12)
#4 TickerMode.getNotifier (package:flutter/src/widgets/ticker_provider.dart:98:50)
#5 TickerProviderStateMixin._updateTickerModeNotifier (package:flutter/src/widgets/ticker_provider.dart:330:58)
#6 TickerProviderStateMixin.createTicker (package:flutter/src/widgets/ticker_provider.dart:294:7)
#7 new AnimationController.unbounded (package:flutter/src/animation/animation_controller.dart:278:21)
#8 new DrivenScrollActivity (package:flutter/src/widgets/scroll_activity.dart:624:39)
#9 ScrollPositionWithSingleContext.animateTo (package:flutter/src/widgets/scroll_position_with_single_context.dart:186:43)
#10 PageController.animateToPage (package:flutter/src/widgets/page_view.dart:199:21)
#11 _TransformerPageViewState.onChangeNotifier (package:card_swiper/src/transformer_page_view/transformer_page_view.dart:583:14)
#12 ChangeNotifier.notifyListeners (package:flutter/src/foundation/change_notifier.dart:403:24)
#13 IndexController.next (package:card_swiper/src/transformer_page_view/index_controller.dart:110:5)
#14 _SwiperTimerMixin._onTimer (package:card_swiper/src/swiper.dart:391:24)
#15 _Timer._runTimers (dart:isolate-patch/timer_impl.dart:398:19)
#16 _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:429:5)
#17 _RawReceivePort._handleMessage (dart:isolate-patch/isolate_patch.dart:189:12)