Flutter > 提供商 > Firebase |无法流式传输一个对象，但另一个流式传输良好并且它们都非常相似

Question

我正在使用 flutter 和 provider 以及 firbase。当流式传输产品列表时，它流式传输良好。但是当想流订单时return 没什么事。请帮助我

这是产品和订单class


class Order {
  final String id;
  final String uid;
  final String email;
  final String status;
  final int total;

  Order({
    this.id,
    this.uid,
    this.email,
    this.status,
    this.total,
  });

  Order.fromFire(DocumentSnapshot doc)
      : id = doc.documentID,
        uid = doc['uid'],
        email = doc['email'],
        status = doc['status'],
        total = doc['total'];
}


import 'package:cloud_firestore/cloud_firestore.dart';

class Product {
  final String id;
  final String name;
  final int price;

  Product({
    this.id,
    this.name,
    this.price,
  });

  Product.fromFire(DocumentSnapshot doc)
      : id = doc.documentID,
        name = doc['name'],
        price = doc['price'];
}

这里是溪流

  Stream<List<Product>> getProductList() {
    return products.snapshots().map((snapShot) => snapShot.documents
        .map(
          (document) => Product.fromFire(document),
        )
        .toList());
  }

  Stream<List<Order>> getOrderList() {
    return orders.snapshots().map((snapShot) => snapShot.documents
        .map(
          (document) => Order.fromFire(document),
        )
        .toList());
  }

这里是供应商

FirebaseService _db = FirebaseService();

        StreamProvider(
          create: (context) => _db.getProductList(),
          catchError: (_, __) => null,
        ),
        StreamProvider(
          create: (context) => _db.getOrderList(),
          catchError: (_, __) => null,
        ),

并使用

读取流

    List<Order> orderList = Provider.of<List<Order>>(context) ?? [];
    List<Product> productList = Provider.of<List<Product>>(context) ?? [];

但产品长度为 5，订单长度为 0，并且在 firestore 中有一些订单

I/flutter (15121): product length 5
I/flutter (15121): order length 0

Answer 1

我发现我的错误是在 Order 模型中我为订单总价定义了 int，当在服务中下订单时，总价是双倍！:)

class Order {
  final String id;
  final String uid;
  final String email;
  final String status;
  final int total;
...

  placeOrder(
    FirebaseUser user,
    Address address,
    List<Product> products,
  ) async {
    String orderid = user.email + ' ' + DateTime.now().toString();
    double total = 0;
    for (int i = 0; i < products.length; i++) {
      total = products[i].price + total;
    }
...

Flutter > 提供商 > Firebase |无法流式传输一个对象，但另一个流式传输良好并且它们都非常相似

Flutter > Provider > Firebase | can't stream one object but another is streaming well and both of them really similar

provider

dart

firebase

flutter

google-cloud-firestore