Flutter 激活复选框时保持下拉菜单打开

我有一个代码，负责按特定类别进行过滤(为了便于阅读，我缩短了它).当打开过滤器窗口时，用户会看到这些类别名称(" Select 品牌"、" Select 操作系统"、" Select colored颜色 "等).

接下来，用户可以打开类别(最初，下拉列表处于关闭位置)，然后从下拉列表中 Select 参数(并单击应用按钮).下次打开"过滤器"窗口时，参数前面的复选框将保留，但下拉列表将折叠.

告诉我怎么做:如果在任何类别中有带有复选标记的选项，那么下拉列表将在下次打开带有过滤器的窗口时打开.

     class FilterDialog extends StatefulWidget {
  final void Function(Map<String, List<String>?>) onApplyFilters;

  final Map<String, List<String>?> initialState;

  const FilterDialog({
    Key? key,
    required this.onApplyFilters,
    this.initialState = const {},
  }) : super(key: key);

  @override
  State<FilterDialog> createState() => _FilterDialogState();
}

class _FilterDialogState extends State<FilterDialog> {
  // Temporary storage of filters.
  Map<String, List<String>?> filters = {};
  bool needRefresh = false;

  // Variable for the ability to hide all elements of filtering by any parameter.
  bool isClickedBrand = false;


  List manufacturer = [];


  @override
  void initState() {
    super.initState();
    filters = widget.initialState;
  }

  // A function to be able to select an element to filter.
  void _handleCheckFilter(bool checked, String key, String value) {
    final currentFilters = filters[key] ?? [];
    if (checked) {
      currentFilters.add(value);
    } else {
      currentFilters.remove(value);
    }
    setState(() {
      filters[key] = currentFilters;
    });
  }

  // Building a dialog box with filters.
  @override
  Widget build(BuildContext context) {
    return SimpleDialog(
      // Window title.

      title: const Text('Filters',
          textAlign: TextAlign.center,
          style: TextStyle(
            fontSize: 25,
            fontWeight: FontWeight.w600,
          )),
      contentPadding: const EdgeInsets.all(16),

      // Defining parameters for filtering.
      children: [
        Column(
          mainAxisSize: MainAxisSize.min,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            // Here and in subsequent Column, there will be a definition of parameters for filtering,
            // a title, the ability to hide/show the items of list
            Column(children: [
              InkWell(
                  onTap: () async {
                    manufacturer = await getManufacturerOptions();
                    setState(() {
                      isClickedBrand = !isClickedBrand;
                    });
                  },
                  child: Row(children: [
                    Text('Select a brand'.toString(),
                        style: const TextStyle(
                          fontSize: 18,
                        )),
                    const Spacer(),
                    isClickedBrand
                        ? const Icon(Icons.arrow_circle_up)
                        : const Icon(Icons.arrow_circle_down)
                  ])),
              !isClickedBrand
                  ? Container()
                  : Column(
                      children: manufacturer
                          .map(
                            (el) => CustomCheckboxTile(
                              value: filters['manufacturer']?.contains(el) ??
                                  false,
                              label: el,
                              onChange: (check) =>
                                  _handleCheckFilter(check, 'manufacturer', el),
                            ),
                          )
                          .toList())
            ]),
            const SizedBox(
              height: 5,
            ),



            // Building a button to apply parameters.
            const SizedBox(
              height: 10,
            ),
            ElevatedButton(
                onPressed: () {
                  Navigator.of(context).pop();
                  widget.onApplyFilters(filters);
                  needRefresh = true;
                },
                child:
                    const Text('APPLY', style: TextStyle(color: Colors.black)),
                style: ButtonStyle(
                  backgroundColor: MaterialStateProperty.all(Colors.grey),
                )),

            // Building a button to reset parameters.
            const SizedBox(
              height: 5,
            ),
            ElevatedButton(
                onPressed: () async {
                  setState(() {
                    filters.clear();
                  });
                  widget.onApplyFilters(filters);
                },
                child: const Text('RESET FILTERS',
                    style: TextStyle(color: Colors.black)),
                style: ButtonStyle(
                  backgroundColor: MaterialStateProperty.all(Colors.grey),
                )),
          ],
        ),
      ],
    );
  }
}

例如:用户单击过滤器框， Select 要搜索的品牌，然后单击应用按钮.我的任务是，下次用户打开过滤器窗口时，带有活动复选框的类别(在本例中为品牌)处于展开状态