flutter - 未处理的异常 : Converting object to an encodable object failed: Photography

Question

我的 cloud_firestore 看起来像这样:

all_images:{imageUrl:[]}, couplePhoto:String, female:String, image_url:String, info:String, male:String

我的模型类:

import 'package:json_annotation/json_annotation.dart';
part 'Model.g.dart';

@JsonSerializable()
class Photography {
  final List<AllImages> all_images;
  final String couplePhoto;
  final String female;
  final String image_url;
  final String info;
  final String male;

  Photography(this.all_images, this.couplePhoto, this.female, this.image_url,
      this.info, this.male);

  factory Photography.fromJson(Map<String, dynamic> json) =>
      _$PhotographyFromJson(json);

  Map<String, dynamic> toJson() => _$PhotographyToJson(this);
}

@JsonSerializable()
class AllImages {
  final List<String> imageUrl;

  AllImages(this.imageUrl);

  factory AllImages.fromJson(Map<String, dynamic> json) =>
      _$AllImagesFromJson(json);

  Map<String, dynamic> toJson() => _$AllImagesToJson(this);
}

目前，我还没有用于数据插入的 adminPanel。所以，现在我需要读取数据。运行这个数据库时，错误就在这里。

    Future<Photography> postsMap = Firestore.instance
        .collection('photography')
        .document("0yUc5QBGHNNq6WK9CyyF")
        .setData(jsonDecode(jsonEncode(Photography)));

Answer 1

在这一行:

.setData(jsonDecode(jsonEncode(Photography)));

您正在引用 Photograph 类的 Type 对象，而不是您需要传递一个实例(因此您需要使用所需的值调用构造函数，并传递其结果)。

.setData(jsonDecode(jsonEncode(Photography(<pass-in-constructor-args-here>))));