问如何使我的旋转木马自动滑行

EN

[VERBOSE-2:ui_dart_state.cc(198)] Unhandled Exception: 'package:flutter/src/widgets/scroll_controller.dart': Failed assertion: line 107 pos 12: '_positions.isNotEmpty': ScrollController not attached to any scroll views.
#0      _AssertionError._doThrowNew (dart:core-patch/errors_patch.dart:51:61)
#1      _AssertionError._throwNew (dart:core-patch/errors_patch.dart:40:5)
#2      ScrollController.position (package:flutter/src/widgets/scroll_controller.dart:107:12)
#3      PageController.animateToPage (package:flutter/src/widgets/page_view.dart:197:41)
#4      _CarouselWidgetState.initState.<anonymous closure> (package:flyzik/widgets/carousel_widget.dart:36:23)
#5      _rootRunUnary (dart:async/zone.dart:1434:47)
#6      _CustomZone.runUnary (dart:async/zone.dart:1335:19)
#7      _CustomZone.runUnaryGuarded (dart:async/zone.dart:1244:7)
#8      _CustomZone.bindUnaryCallbackGuarded.<anonymous closure> (dart:async/zone.dart:1281:26)
#9      _rootRunUnary (dart:async/zone.dart:1442:13)
#10     _CustomZone.<…>

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

  @override
  State<CarouselWidget> createState() => _CarouselWidgetState();
}

class _CarouselWidgetState extends State<CarouselWidget> {
  int _currentIndex = 0;
  late PageController _pageController;
  late Timer _timer;
  @override
  void initState() {
    _pageController = PageController(initialPage: 0);
    _timer = Timer.periodic(const Duration(seconds: 4), (Timer timer) {
      if (_currentIndex < 5 - 1) {
        _currentIndex++;
      } else {
        _currentIndex = 0;
      }

      _pageController.animateToPage(
        _currentIndex,
        duration: const Duration(milliseconds: 350),
        curve: Curves.easeOutCubic,
      );
    });
    super.initState();
  }

  @override
  void dispose() {
    _pageController.dispose();
    _timer.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return StreamBuilder<List<CarouselModel>>(
        stream: DBServices().getCarousels,
        builder: (context, snapshot) {
          if (snapshot.hasError) {
            return Center(
              child: Text('Erreur: ' + snapshot.error.toString()),
            );
          }
          if (snapshot.connectionState == ConnectionState.waiting) {
            return Shimmer.fromColors(
              baseColor: kShimmerBaseColor,
              highlightColor: kShimmerHifhtLightColor,
              child: Container(
                width: double.infinity,
                height: 220,
                decoration: BoxDecoration(
                    borderRadius: BorderRadius.circular(10),
                    color: Colors.grey),
              ),
            );
          }
          final carousels = snapshot.data;
          return AspectRatio(
                  aspectRatio: 1.81,
                  child: Stack(
                    alignment: Alignment.bottomRight,
                    children: [
                      PageView.builder(
                        itemCount: carousels!.length,
                        controller: _pageController,
                        onPageChanged: (value) {
                          setState(() {
                            _currentIndex = value;
                            print("current index: $value");
                            print("current index2: $_currentIndex");
                          });
                        },
                        itemBuilder: (context, index) => ClipRRect(
                          borderRadius: BorderRadius.all(Radius.circular(12)),
                          child: CachedNetworkImage(
                            imageUrl: carousels[index].imageUrl,
                            fit: BoxFit.cover,
                          ),
                        ),
                      ),
                      Positioned(
                        bottom: defaultPadding,
                        right: defaultPadding,
                        child: Padding(
                          padding:
                              const EdgeInsets.only(left: defaultPadding / 4),
                          child: Row(
                            children: List.generate(
                                carousels.length,
                                (index) => IndicatorDot(
                                    isActive: index == _currentIndex)),
                          ),
                        ),
                      ),
                    ],
                  ),
                );
        });
  }
}

class IndicatorDot extends StatelessWidget {
  const IndicatorDot({
    Key? key,
    required this.isActive,
  }) : super(key: key);
  final bool isActive;

  @override
  Widget build(BuildContext context) {
    return Container(
      height: getProportionateScreenHeight(4),
      width: getProportionateScreenWidth(8),
      decoration: BoxDecoration(
        color: isActive ? kBlack : Colors.white38,
        borderRadius: BorderRadius.all(
          Radius.circular(getProportionateScreenWidth(12)),
        ),
      ),
    );
  }
}