FireStore 错误的 Map<String, dynamic>

Question

正在尝试为来自 FireStore 的项目创建映射：

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);

然而，_toInt in the hero(_toInt(hero['id']...给出错误："Instance members can't be accessed from a factory constructor"

我错过了什么？ AngularDart 英雄之旅在他们的 GitHub sample 上是这样的。

hero_service 获得英雄召唤：

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

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

让 _toInt 静态，你就是金色的。

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