预期值为"() =>动态"，但得到类型为 'IdentityMap<String, bool>'

Question

我制作的膳食应用程序使用扑动和本地数据从虚拟数据

链接github项目https://github.com/rowanibrahem/meal.git

我想让过滤器用户选择的膳食成分并保存它，并使过滤的膳食只有这个成分但这个错误，我无法处理它

在main.dart

void _setFilters(Map<String, bool> _filterData) {
setState(() {
_filters = _filterData;
_availableMeals = DUMMY_MEALS.where((meal) {
if (_filters['gluten']! && !meal.isGlutenFree) {
return false;
}
if (_filters['lactose']! && !meal.isLactoseFree) {
return false;
}
if (_filters['vegan']! && !meal.isVegan) {
return false;
}
if (_filters['vegetarian']! && !meal.isVegetarian) {
return false;
}
return true;
}).toList();
});
}
/// routes
routes: {
//...
FiltersScreen.routeName: (context) =>
FiltersScreen(_filters as Function() , _setFilters as Map<String, bool>),
},

滤镜页

class FiltersScreen extends StatefulWidget {
static const routeName = '/filters';
final Function() saveFilters;
final Map<String , bool> currentFilters;
FiltersScreen(this.saveFilters, this.currentFilters);
@override
State<FiltersScreen> createState() => _FiltersScreenState();
}

Answer 1

当您使用位置参数时，它可能会令人困惑，更好的做法是在方法上使用命名参数。现在让我们继续使用当前的编码风格。

FiltersScreen按此顺序接受

FiltersScreen(this.saveFilters, this.currentFilters);

但是这里的参数传递顺序错误。

FiltersScreen.routeName: (context) =>
FiltersScreen(_filters as Function() , _setFilters as Map<String, bool>),

您还想从回调中获取项目，这将是

class FiltersScreen extends StatefulWidget {
static const routeName = '/filters';
final Function(Map<String, bool> _filterData) saveFilters;
final Map<String, bool> currentFilters;
const FiltersScreen(this.saveFilters, this.currentFilters);
@override
State<FiltersScreen> createState() => _FiltersScreenState();
}

And on main。飞镖路线,

FiltersScreen.routeName: (context) =>
FiltersScreen(_setFilters, _filters),