不能将 'List<Object?> 的值类型分配给 'List<Looking Gender> 类型的变量

Question

所以，我想做的是使用 multi_select_dropdown 允许约会应用程序的用户 select 多种事物，例如性别和取向，但我不断收到变量错误在主题中。这是我宣布名单的地方：

static List<LookingGender> _lookingGender = [
        LookingGender(id: 1, name: 'Male'),
        LookingGender(id: 2, name: 'Female'),
    LookingGender(id: 3, name: 'TransMale'),
    LookingGender(id: 4, name: 'TransFemale'),
    LookingGender(id: 5, name: 'Non-Binary'),
    LookingGender(id: 6, name: 'Agender'),
    LookingGender(id: 7, name: 'Androgynous'),
    LookingGender(id: 8, name: 'Genderfluid'),
    LookingGender(id: 9, name: 'Genderqueer'),
    LookingGender(id: 10, name: 'Intersex'),
    LookingGender(id: 11, name: 'Two Spirit'),
    ];
    final _selectedLookingGender = _lookingGender
      .map((lookingGender) =>
          MultiSelectItem<LookingGender>(lookingGender, lookingGender.name))
      .toList();
    List<LookingGender> _selectedLookingGender2 = [];
    List<LookingGender> _selectedLookingGender3 = [];
    List<LookingGender> _selectedLookingGender5 = [];
    final _multiSelectKey = GlobalKey<FormFieldState>();

    static List<LookingOrientation> _lookingOrientation = [
      LookingOrientation(id: 1, name: 'Heterosexual'),
      LookingOrientation(id: 2, name: 'Homosexual'),
      LookingOrientation(id: 3, name: 'Lesbian'),
      LookingOrientation(id: 4, name: 'Gay'),
      LookingOrientation(id: 5, name: 'Demisexual'),
      LookingOrientation(id: 6, name: 'Pansexual'),
      LookingOrientation(id: 7, name: 'Asexual'),
      LookingOrientation(id: 8, name: 'Bisexual'),
      LookingOrientation(id: 9, name: 'Bicurious'),
      ];
    final _selectedLookingOrientation = _lookingOrientation
      .map((lookingOrientation) => MultiSelectItem<LookingOrientation>(
          lookingOrientation, lookingOrientation.name))
      .toList();
    List<LookingOrientation> _selectedLookingOrientation2 = [];
    List<LookingOrientation> _selectedLookingOrientation3 = [];
    List<LookingOrientation> _selectedLookingOrientation5 = [];

这就是事情变得不稳定的地方。错误似乎在 'values' 变量上。

 // Looking for Gender field
                    Container(
                      decoration: BoxDecoration(
                        color: Theme.of(context).primaryColor.withOpacity(0.4),
                        border: Border.all(
                          color: Theme.of(context).primaryColor,
                          width: 2,
                        ),
                      ),
                      child: Column(
                        children: <Widget>[
                          MultiSelectBottomSheetField(
                            initialChildSize: 0.4,
                            listType: MultiSelectListType.CHIP,
                            searchable: true,
                            buttonText: Text('Looking for Gender'),
                            title: Text('Genders'),
                            items: _selectedLookingGender,
                            onConfirm: (values) {
                              _selectedLookingGender2 = values;
                            },
                            chipDisplay: MultiSelectChipDisplay(
                              onTap: (value) {
                                setState(() {
                                  _selectedLookingGender2.remove(value);
                                });
                              },
                            ),
                          ),
                          _selectedLookingGender2 == null ||
                                  _selectedLookingGender2.isEmpty
                              ? Container(
                                  padding: EdgeInsets.all(10),
                                  alignment: Alignment.centerLeft,
                                  child: const Text(
                                    "None Selected",
                                    style: TextStyle(color: Colors.black54),
                                  ))
                              : Container(),
                        ],
                      ),
                    ),

                    SizedBox(height: 20),

                    MultiSelectChipField<LookingGender>(
                      items: _selectedLookingGender,
                      initialValue: [_lookingGender[1]],
                      title: const Text('Genders'),
                      headerColor: Colors.blue.withOpacity(0.5),
                      decoration: BoxDecoration(
                        border:
                            Border.all(color: (Colors.blue[700]!), width: 1.8),
                      ),
                      selectedChipColor: Colors.blue.withOpacity(0.5),
                      selectedTextStyle: TextStyle(color: Colors.blue[800]),
                      onTap: (values) {},
                    ),
                    const SizedBox(height: 20),

                    // Looking for Orientation field
                    Container(
                      decoration: BoxDecoration(
                        color: Theme.of(context).primaryColor.withOpacity(0.4),
                        border: Border.all(
                          color: Theme.of(context).primaryColor,
                          width: 2,
                        ),
                      ),
                      child: Column(
                        children: <Widget>[
                          MultiSelectBottomSheetField(
                            initialChildSize: 0.4,
                            listType: MultiSelectListType.CHIP,
                            searchable: true,
                            buttonText: Text('Looking for Gender'),
                            title: Text('Genders'),
                            items: _selectedLookingGender,
                            onConfirm: (values) {
                              _selectedLookingGender2 = values;
                            },
                            chipDisplay: MultiSelectChipDisplay(
                              onTap: (value) {
                                setState(() {
                                  _selectedLookingGender2.remove(value);
                                });
                              },
                            ),
                          ),
                          _selectedLookingGender2 == null ||
                                  _selectedLookingGender2.isEmpty
                              ? Container(
                                  padding: EdgeInsets.all(10),
                                  alignment: Alignment.centerLeft,
                                  child: const Text(
                                    "None Selected",
                                    style: TextStyle(color: Colors.black54),
                                  ))
                              : Container(),
                        ],
                      ),
                    ),
                    MultiSelectChipField(
                      items: _selectedLookingOrientation,
                      initialValue: [_lookingOrientation[1]],
                      title: const Text('Orientation'),
                      headerColor: Colors.blue.withOpacity(0.5),
                      decoration: BoxDecoration(
                        border:
                            Border.all(color: (Colors.blue[700]!), width: 1.8),
                      ),
                      selectedChipColor: Colors.blue.withOpacity(0.5),
                      selectedTextStyle: TextStyle(color: Colors.blue[800]),
                      onTap: (values) {},
                    ),
                    const SizedBox(height: 20),

我是这方面的新手，所以这是一段痛苦的旅程。

Answer 1

你可以试试这个：

MultiSelectBottomSheetField(
                        initialChildSize: 0.4,
                        listType: MultiSelectListType.CHIP,
                        searchable: true,
                        buttonText: Text('Looking for Gender'),
                        title: Text('Genders'),
                        items: _selectedLookingGender,
                        onConfirm: (values) {
                          List<LookingGender> tempSelectedLookingGender = [];

                          var newValues = values as List<MultiSelectItem<LookingGender>>;
                          newValues.forEach((element) {
                            tempSelectedLookingGender.add(element.value);
                          });

                          _selectedLookingGender2 = tempSelectedLookingGender;
                        },
                        chipDisplay: MultiSelectChipDisplay(
                          onTap: (value) {
                            setState(() {
                              _selectedLookingGender2.remove(value);
                            });
                          },
                        ),
                      ),

不能将 'List<Object?> 的值类型分配给 'List<Looking Gender> 类型的变量

A value type of 'List<Object?> can't be assigned to a variable of type 'List<Looking Gender>

variables

list

dart

flutter