使 Stream 能够从 Cloud Firestore Flutter 获取数据

Question

我想从我的 Cloud Firestore 数据库集合中获取数据。我尝试使用流，但似乎它不起作用，因为我无法在控制台上打印这些数据并在屏幕上获取它们。我做错了什么吗？

Stream<List<ProductModel>> getAllProducts() =>
      firebaseFirestore.collection("products").snapshots().map((query) =>
          query.docs.map((item) => ProductModel.fromMap(item.data())).toList());

如果您想知道，这是我的 ProductModel 类，其中包含与我的 firestore 集合相同的属性

class ProductModel {
  static const ID = "id";
  static const IMAGE = "image";
  static const NAME = "name";
  static const BRAND = "brand";
  static const PRICE = "price";

  String? id;
  String? image;
  String? name;
  String? brand;
  double? price;

  ProductModel(
      {required this.id,
      required this.image,
      required this.name,
      required this.brand,
      required this.price});

  ProductModel.fromMap(Map<String, dynamic> data) {
    id = data[ID];
    image = data[IMAGE];
    name = data[NAME];
    brand = data[BRAND];
    price = data[PRICE].toDouble();
  }
}