我试图在 BottomNavigationBar 中调用一个列表（（位于 build(BuildContext context) 小部件之外））。该列表包含一个有状态的小部件（包含轮播幻灯片）。因此，当我重新运行我的项目并滚动页面时，我会不断收到此错误。它说
E/flutter ( 6022): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: 'package:flutter/src/widgets/page_view.dart': Failed assertion: line 180 pos 7: 'positions.isNotEmpty': PageController.page cannot be accessed before a PageView is built with it.
E/flutter ( 6022): #0 _AssertionError._doThrowNew (dart:core-patch/errors_patch.dart:42:39)
E/flutter ( 6022): #1 _AssertionError._throwNew (dart:core-patch/errors_patch.dart:38:5)
E/flutter ( 6022): #2 PageController.page (package:flutter/src/widgets/page_view.dart:180:7)
E/flutter ( 6022): #3 CarouselState.initState.<anonymous closure> (package:carousel_pro/src/carousel_pro.dart:110:24)
E/flutter ( 6022): #4 _rootRunUnary (dart:async/zone.dart:1192:38)
E/flutter ( 6022): #5 _CustomZone.runUnary (dart:async/zone.dart:1085:19)
E/flutter ( 6022): #6 _CustomZone.runUnaryGuarded (dart:async/zone.dart:987:7)
E/flutter ( 6022): #7 _CustomZone.bindUnaryCallbackGuarded.<anonymous closure> …