FireStore 错误的 Map<String, dynamic>

Question

尝试为 FireStore 中的项目创建地图，如下所示：

class Hero {
  final int id;
  String name;
  bool pickupNeeded;
  String url;
  bool partPickup;


  Hero(this.id, this.name, this.pickupNeeded, this.url, this.partPickup);


  factory Hero.fromJson(Map<String, dynamic> hero) =>
      Hero(_toInt(hero['id']), hero['name'], hero['pickupNeeded'], hero['url'], hero['partPickup']);

  Map toJson() => {'id' : id, 'name': name, 'pickupNeeded' : pickupNeeded, 'url' : url, 'partPickup' : partPickup,};

  int _toInt(id) => id is int ? id : int.parse(id);

但是，_toInt in the hero(_toInt(hero['id']... 给出错误：“无法从工厂构造函数访问实例成员”

我错过了什么？ AngularDart Tour of Heroes 在他们的GitHub sample 上是这样的。

hero_service 获取英雄召唤：

Future<Hero> get(dynamic id) async {
    try {
      return Hero.fromJson(id);
    } catch (e) {
      throw _handleError(e);
    }
  }

以及调用它的 Hero 组件：

void onActivate(_, RouterState current) async {
    final id = RoutePaths().getId(current.parameters);
    if (id != null) hero = await (_heroService.get(id));
  }

Answer 1

将_toInt 设为静态，你就是金子。

static int _toInt(id) => id is int ? id : int.parse(id);