颤振 - 处理 json 数据

【问题标题】：flutter - handling json data颤振 - 处理 json 数据
【发布时间】：2020-04-20 13:44:34
【问题描述】：

在处理我的应用数据方面需要您的帮助。我已经对我的问题进行了很多研究，但还没有找到有效的答案...

这是我的问题： 我希望我的应用程序显示人骨。我要显示的数据存储在 JSON 文件中（它不是整个 json 文件，因为它只是一遍又一遍地重复。括号不是错误）：

{

"bones": 
    [
    {
        "id": "1",
        "name": "Humerus",
        "image": "assets/images/...",
        "locations": [
            {
            "location1": [
                {
                "id": "11",
                "title": "proximal",
                "image": "assets/images/...",
                "subcategory1": [
                    {
                    "id": "11A",
                    "title": "extraartikulär 2-Segment unifokal",
                    "image": "assets/images/...",
                    "subsubcategory1": [{
                        "id": "11A1",
                        "title": "Abriß des Tuberculum majus",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "11A1.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "11A1.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "11A1.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }],
                    "subsubcategory2": [{
                        "title": "Abriß des Tuberculum majus",
                        "id": "11A2",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "11A2.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "11A2.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "11A2.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }],
                    "subsubcategory3": [{
                        "title": "Abriß des Tuberculum majus",
                        "id": "11A3",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "11A3.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "11A3.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "11A3.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }]
                }],
                "subcategory2": [{
                    "id": "11B",
                    "title": "extraartikulär 2-Segment unifokal",
                    "image": "assets/images/...",
                    "subsubcategory1": [{
                        "id": "11B1",
                        "title": "Abriß des Tuberculum majus",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "11B1.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "11B1.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "11B1.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }],
                    "subsubcategory2": [{
                        "title": "Abriß des Tuberculum majus",
                        "id": "11B2",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "11B2.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "11B2.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "11B2.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }],
                    "subsubcategory3": [{
                        "title": "Abriß des Tuberculum majus",
                        "id": "11B3",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "11B3.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "11B3.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "11B3.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }]
                }],
                "subcategory3": [{
                    "id": "11C",
                    "title": "extraartikulär 2-Segment unifokal",
                    "image": "assets/images/...",
                    "subsubcategory1": [{
                        "id": "11C1",
                        "title": "Abriß des Tuberculum majus",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "11C1.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "11C1.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "11C1.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }],
                    "subsubcategory2": [{
                        "title": "Abriß des Tuberculum majus",
                        "id": "11C2",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "11C2.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "11C2.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "11C2.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }],
                    "subsubcategory3": [{
                        "title": "Abriß des Tuberculum majus",
                        "id": "11C3",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "11C3.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "11C3.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "11C3.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }]
                }]

            }],
            "location2": [
                {
                "id": "12",
                "title": "diaphysär",
                "image": "assets/images/...",
                "subcategory1": [{
                    "id": "12A",
                    "title": "extraartikulär 2-Segment unifokal",
                    "image": "assets/images/...",
                    "subsubcategory1": [{
                        "id": "12A1",
                        "title": "Abriß des Tuberculum majus",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "12A1.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "12A1.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "12A1.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }],
                    "subsubcategory2": [{
                        "title": "Abriß des Tuberculum majus",
                        "id": "12A2",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "11A2.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "12A2.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "12A2.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }],
                    "subsubcategory3": [{
                        "title": "Abriß des Tuberculum majus",
                        "id": "12A3",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "12A3.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "12A3.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "12A3.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }]
                }],
                "subcategory2": [{
                    "id": "12B",
                    "title": "extraartikulär 2-Segment unifokal",
                    "image": "assets/images/...",
                    "subsubcategory1": [{
                        "id": "12B1",
                        "title": "Abriß des Tuberculum majus",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "12B1.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "12B1.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "12B1.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }],
                    "subsubcategory2": [{
                        "title": "Abriß des Tuberculum majus",
                        "id": "12B2",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "12B2.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "12B2.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "12B2.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }],
                    "subsubcategory3": [{
                        "title": "Abriß des Tuberculum majus",
                        "id": "12B3",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "12B3.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "12B3.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "12B3.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }]
                }],
                "subcategory3": [{
                    "id": "12C",
                    "title": "extraartikulär 2-Segment unifokal",
                    "image": "assets/images/...",
                    "subsubcategory1": [{
                        "id": "12C1",
                        "title": "Abriß des Tuberculum majus",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "12C1.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "12C1.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "12C1.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }],
                    "subsubcategory2": [{
                        "title": "Abriß des Tuberculum majus",
                        "id": "12C2",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "11C2.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "12C2.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "12C2.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }],
                    "subsubcategory3": [{
                        "title": "Abriß des Tuberculum majus",
                        "id": "12C3",
                        "image": "assets/images/...",
                        "final_item1": {
                            "id": "11C3.1",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item2": {
                            "id": "12C3.2",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        },
                        "final_item3": {
                            "id": "12C3.3",
                            "title": "Tuberculum majus ohne Dislokation",
                            "image": "assets/images/...",
                            "model": "assets/images/..."
                        }
                    }]
                }]

            }]

        }]
    }
]}

有 3 个地点，每个地点有 3 个子类别，每个 3 个子子类别，每 3 个最终项目。

目前我只是试图在控制台中打印骨骼的名称。我有这些课程：

class Bone {
  final String id;
  final String name;
  final String imageUrl;
  final List<Locations> locations;

  Bone({this.id, this.imageUrl, this.name, this.locations});
  factory Bone.fromJson(Map<String, dynamic> json){
    return Bone(
    id: json['id'],
    name: json['name'],
    imageUrl: json['image'],
    locations: json['locations']
    );
  }
}

class Locations{
  final List<Location> location;

  Locations(this.location);
}

class Location{
  final String id;
  final String title;
  final String imageUrl;
  final List<Subcategory> subcategory;

  Location({this.id, this.title, this.imageUrl, this.subcategory});
}

class Subcategory{
  final String id;
  final String title;
  final String imageUrl;
  final List<Subsubcategory> subsubcategory;

  Subcategory({this.id, this.title, this.imageUrl, this.subsubcategory});
}

class Subsubcategory{
  final String id;
  final String title;
  final String imageUrl;
  final FinalItem finalItem;

  Subsubcategory({this.id, this.title, this.imageUrl, this.finalItem});
}

class FinalItem{
  final String id;
  final String title;
  final String imageUrl;

  FinalItem({this.id, this.title, this.imageUrl});
}

还有这个测试画面：

import 'dart:convert';
import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import '../models/bone.dart';

class TestScreen extends StatefulWidget {

  static const routeName = '/test';

  @override
  _TestScreenState createState() => _TestScreenState();
}

class _TestScreenState extends State<TestScreen> {


  Future<String> loadDataFromAssets() async {
    return await rootBundle.loadString('assets/api/data.json');
  }

  Future loadData() async {
    String jsonString = await loadDataFromAssets();
    final jsonResponse = json.decode(jsonString);
    Bone bone = Bone.fromJson(jsonResponse);
    print('Name ${bone.name}');
  }

  @override
  void initState() {
    super.initState();
    loadData();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("test")),

    );
  }
}

在我的调试控制台中抛出此错误：

E/flutter (7644): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] 未处理的异常：“List”类型不是“List”类型的子类型

提前谢谢你:)

https://pastebin.com/utpKhnYx

【问题讨论】：

    标签： json flutter


    【解决方案1】：

    型号：

    class Bone {
  List<Bones> bones;

  Bone({this.bones});

  Bone.fromJson(Map<String, dynamic> json) {
    if (json['bones'] != null) {
      bones = new List<Bones>();
      json['bones'].forEach((v) {
        bones.add(new Bones.fromJson(v));
      });
    }
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    if (this.bones != null) {
      data['bones'] = this.bones.map((v) => v.toJson()).toList();
    }
    return data;
  }
}

class Bones {
  String id;
  String name;
  String image;
  List<Locations> locations;

  Bones({this.id, this.name, this.image, this.locations});

  Bones.fromJson(Map<String, dynamic> json) {
    id = json['id'];
    name = json['name'];
    image = json['image'];
    if (json['locations'] != null) {
      locations = new List<Locations>();
      json['locations'].forEach((v) {
        locations.add(new Locations.fromJson(v));
      });
    }
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['id'] = this.id;
    data['name'] = this.name;
    data['image'] = this.image;
    if (this.locations != null) {
      data['locations'] = this.locations.map((v) => v.toJson()).toList();
    }
    return data;
  }
}

class Locations {
  List<Location> location1;
  List<Location> location2;
  List<Location> location3;

  Locations({this.location1, this.location2, this.location3});

  Locations.fromJson(Map<String, dynamic> json) {
    if (json['location1'] != null) {
      location1 = new List<Location>();
      json['location1'].forEach((v) {
        location1.add(new Location.fromJson(v));
      });
    }
    if (json['location2'] != null) {
      location2 = new List<Location>();
      json['location2'].forEach((v) {
        location2.add(new Location.fromJson(v));
      });
    }
    if (json['location3'] != null) {
      location3 = new List<Location>();
      json['location3'].forEach((v) {
        location3.add(new Location.fromJson(v));
      });
    }
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    if (this.location1 != null) {
      data['location1'] = this.location1.map((v) => v.toJson()).toList();
    }
    if (this.location2 != null) {
      data['location2'] = this.location2.map((v) => v.toJson()).toList();
    }
    if (this.location3 != null) {
      data['location3'] = this.location3.map((v) => v.toJson()).toList();
    }
    return data;
  }
}

class Location {
  String id;
  String title;
  String image;
  List<Subcategory> subcategory1;
  List<Subcategory> subcategory2;
  List<Subcategory> subcategory3;

  Location(
      {this.id,
        this.title,
        this.image,
        this.subcategory1,
        this.subcategory2,
        this.subcategory3});

  Location.fromJson(Map<String, dynamic> json) {
    id = json['id'];
    title = json['title'];
    image = json['image'];
    if (json['subcategory1'] != null) {
      subcategory1 = new List<Subcategory>();
      json['subcategory1'].forEach((v) {
        subcategory1.add(new Subcategory.fromJson(v));
      });
    }
    if (json['subcategory2'] != null) {
      subcategory2 = new List<Subcategory>();
      json['subcategory2'].forEach((v) {
        subcategory2.add(new Subcategory.fromJson(v));
      });
    }
    if (json['subcategory3'] != null) {
      subcategory3 = new List<Subcategory>();
      json['subcategory3'].forEach((v) {
        subcategory3.add(new Subcategory.fromJson(v));
      });
    }
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['id'] = this.id;
    data['title'] = this.title;
    data['image'] = this.image;
    if (this.subcategory1 != null) {
      data['subcategory1'] = this.subcategory1.map((v) => v.toJson()).toList();
    }
    if (this.subcategory2 != null) {
      data['subcategory2'] = this.subcategory2.map((v) => v.toJson()).toList();
    }
    if (this.subcategory3 != null) {
      data['subcategory3'] = this.subcategory3.map((v) => v.toJson()).toList();
    }
    return data;
  }
}

class Subcategory {
  String id;
  String title;
  String image;
  List<Subsubcategory> subsubcategory1;
  List<Subsubcategory> subsubcategory2;
  List<Subsubcategory> subsubcategory3;

  Subcategory(
      {this.id,
        this.title,
        this.image,
        this.subsubcategory1,
        this.subsubcategory2,
        this.subsubcategory3});

  Subcategory.fromJson(Map<String, dynamic> json) {
    id = json['id'];
    title = json['title'];
    image = json['image'];
    if (json['subsubcategory1'] != null) {
      subsubcategory1 = new List<Subsubcategory>();
      json['subsubcategory1'].forEach((v) {
        subsubcategory1.add(new Subsubcategory.fromJson(v));
      });
    }
    if (json['subsubcategory2'] != null) {
      subsubcategory2 = new List<Subsubcategory>();
      json['subsubcategory2'].forEach((v) {
        subsubcategory2.add(new Subsubcategory.fromJson(v));
      });
    }
    if (json['subsubcategory3'] != null) {
      subsubcategory3 = new List<Subsubcategory>();
      json['subsubcategory3'].forEach((v) {
        subsubcategory3.add(new Subsubcategory.fromJson(v));
      });
    }
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['id'] = this.id;
    data['title'] = this.title;
    data['image'] = this.image;
    if (this.subsubcategory1 != null) {
      data['subsubcategory1'] =
          this.subsubcategory1.map((v) => v.toJson()).toList();
    }
    if (this.subsubcategory2 != null) {
      data['subsubcategory2'] =
          this.subsubcategory2.map((v) => v.toJson()).toList();
    }
    if (this.subsubcategory3 != null) {
      data['subsubcategory3'] =
          this.subsubcategory3.map((v) => v.toJson()).toList();
    }
    return data;
  }
}

class Subsubcategory {
  String id;
  String title;
  String image;
  FinalItem1 finalItem1;
  FinalItem1 finalItem2;
  FinalItem1 finalItem3;

  Subsubcategory(
      {this.id,
        this.title,
        this.image,
        this.finalItem1,
        this.finalItem2,
        this.finalItem3});

  Subsubcategory.fromJson(Map<String, dynamic> json) {
    id = json['id'];
    title = json['title'];
    image = json['image'];
    finalItem1 = json['final_item1'] != null
        ? new FinalItem1.fromJson(json['final_item1'])
        : null;
    finalItem2 = json['final_item2'] != null
        ? new FinalItem1.fromJson(json['final_item2'])
        : null;
    finalItem3 = json['final_item3'] != null
        ? new FinalItem1.fromJson(json['final_item3'])
        : null;
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['id'] = this.id;
    data['title'] = this.title;
    data['image'] = this.image;
    if (this.finalItem1 != null) {
      data['final_item1'] = this.finalItem1.toJson();
    }
    if (this.finalItem2 != null) {
      data['final_item2'] = this.finalItem2.toJson();
    }
    if (this.finalItem3 != null) {
      data['final_item3'] = this.finalItem3.toJson();
    }
    return data;
  }
}

class FinalItem1 {
  String id;
  String title;
  String image;
  String model;

  FinalItem1({this.id, this.title, this.image, this.model});

  FinalItem1.fromJson(Map<String, dynamic> json) {
    id = json['id'];
    title = json['title'];
    image = json['image'];
    model = json['model'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['id'] = this.id;
    data['title'] = this.title;
    data['image'] = this.image;
    data['model'] = this.model;
    return data;
  }
}

    测试屏幕：

    class TestScreen extends StatefulWidget {

  static const routeName = '/test';

  @override
  _TestScreenState createState() => _TestScreenState();
}

class _TestScreenState extends State<TestScreen> {


  Future<String> loadDataFromAssets() async {
    return await rootBundle.loadString('assets/api/data.json');
  }

  Future loadData() async {
    String jsonString = await loadDataFromAssets();
    final jsonResponse = json.decode(jsonString);
    Bone bone = Bone.fromJson(jsonResponse);
    print('Name ${bone.bones[0].name}');
  }

  @override
  void initState() {
    super.initState();
    loadData();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("test")),

    );
  }
}

    【讨论】：

    • 不幸的是，这不起作用。 '我/颤动（7644）：名称：空'
    • 我还收到了编译器消息：lib/models/bone.dart:13:66：错误：找不到方法：'Locations.fromJson'。位置： (json['locations'] as List)?.map((i) => Locations.fromJson(i))?.toList()
    • 您的模型不正确。请为您的所有模型添加 fromJson 方法。它将修复它。
    • 你可以共享一个json对象，我会生成模型给你理解。
    • 我从 json 方法添加到每个类，但它仍然返回 null -.- 这很好，但我不明白你的意思
    猜你喜欢
    • 2020-12-25
    • 1970-01-01
    • 2020-11-09
    • 2020-12-05
    • 2022-01-05
    • 2019-11-27
    • 2021-03-17
    • 2022-01-05
    • 2021-03-26
    相关资源
    最近更新 更多
    热门标签
    Java Python linux javascript Mysql C# Docker 算法 前端 SpringBoot Redis Vue spring 设计模式 .net core .net kubernetes c++ 数据库 数据结构 大数据 js 机器学习 微服务 Android Go 程序员 面试 JVM ASP.net core 云原生 人工智能 后端 PHP git CSS golang k8s Nginx Django mybatis 深度学习 多线程 React 架构 devops 爬虫 云计算 Spring Boot LeetCode