问是否有办法对小部件进行有条件的重新生成？

EN

class NumberColViewContainer extends StatelessWidget {
  /// A bool to indicate that you have passed a set of 3 digits and starting a new one
  final bool comma;

  /// The [TextStyle] of the number
  final TextStyle textStyle;
  // The [Duration] the animation will take to slide the number into place
  final Duration duration;
  // The curve that is used during the animation
  final Curve curve;

  NumberColViewContainer(
      {@required this.textStyle,
      @required this.duration,
      this.comma = false,
      @required this.curve});
  @override
  Widget build(BuildContext context) {
    return StoreConnector<AppState, _ViewModel>(
      builder: (context, vm) {
        return NumberColView(
          animateTo: vm.position,
          textStyle: textStyle,
          duration: duration,
          curve: curve,
          comma: comma
        );
      },
      converter: _ViewModel.fromStore,
      distinct: true,
    );
  }
}

class _ViewModel {
  _ViewModel({
    this.position,
    // this.store
  });

  final int  position;
  // final Store<AppState> store;

  static _ViewModel fromStore(Store<AppState> store) {
    return _ViewModel(
      position: store.state.numberSlideEpicPositionState.position,
      // store: store,
    );
  }
}

class NumberColView extends StatefulWidget {
  final int animateTo;
  final bool comma;
  final TextStyle textStyle;
  final Duration duration;
  final Curve curve;

  NumberColView(
      {@required this.animateTo,
      @required this.textStyle,
      @required this.duration,
      this.comma = false,
      @required this.curve})
      : assert(animateTo != null && animateTo >= 0 && animateTo < 10);

  @override
  _NumberColState createState() => _NumberColState();
}

class _NumberColState extends State<NumberColView>
    with SingleTickerProviderStateMixin {
  ScrollController _scrollController;

  double _elementSize = 0.0;

  @override
  void initState() {
    super.initState();
    _scrollController = new ScrollController();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      _elementSize = _scrollController.position.maxScrollExtent / 10;
      setState(() {});

      _scrollController.animateTo(_elementSize * widget.animateTo,
          duration: widget.duration, curve: widget.curve);
    });
  }


@override
  void didUpdateWidget(NumberColView oldWidget) {
    if (oldWidget.animateTo != widget.animateTo) {
      _scrollController.animateTo(
          _elementSize * widget.animateTo,
          duration: widget.duration,
          curve: widget.curve);
    }

    super.didUpdateWidget(oldWidget);
  }
  @override
  Widget build(BuildContext context) {
    // print(widget.animateTo);
    return Row(
      mainAxisSize: MainAxisSize.min,
      children: [
        IgnorePointer(
          child: ConstrainedBox(
            constraints: BoxConstraints(maxHeight: _elementSize),
            child: SingleChildScrollView(
              controller: _scrollController,
              child: Column(
                children: List.generate(10, (position) {
                  return Text(position.toString(), style: widget.textStyle);
                }),
              ),
            ),
          ),
        ),
        widget.comma
            ? Container(
                child: Text(', ',
                    style:
                        TextStyle(fontSize: 16, fontWeight: FontWeight.bold)))
            : Container(),
      ],
    );
  }
}