Flutter：Json解析

Question

我正在尝试在 Flutter 中解析 A​​PI 响应。下面是 API 响应的样子。如何在 Flutter 中解析相同的内容？我想解析所有的值。

fromJson 方法中的parsedJson 参数具有所有值。我确定我的解析有问题。

非常感谢您的帮助！提前致谢。

{
  "responseModel": {
    "data": [
      {
        "offers": {
          "brandName": "Yoga",
          "brandLogo": "364t3.jpg",
          "id": 2214,
          "title": "Up to 40% discount on yoga classes",
          "shortDescription": "<p>Up to 40% discount </p>",
          "categories": null,
          "subcategories": null,
          "offerContactAddress": "<p>Kolkata</p>",
          "offerContactWebsite": "http://www.google.com",
          "offerContactTelephone": "123 456",
          "offerContactEmail": "abcd@gmail.com",
          "offerContactMobileNumber": null,
          "aboutThisOffer": "<p>Yoga is a science of healthy and happy living. </p>",
          "details": [
            {
              "type": "OfferValue",
              "name": "Offer",
              "content": "<p>My Content</p>"
            }
          ],
          "locationDetails": [
            {
              "latitude": "25.32",
              "longitude": "55.23",
              "address": "Kolkata"
            },
            {
              "latitude": "25.1239",
              "longitude": "55.643",
              "address": "Mumbai"
            }
          ],
          "offerValidity": {
            "validFrom": "10/17/2013",
            "validTo": "12/31/2020"
          },
          "keywordList": {
            "keywords": [
              "Yoga",
              "Weight Loss"
            ]
          },
          "images": [
            "20pic2.jpg",
            "20pic1.jpg"
          ],
          "mobileofflineimages": null,
          "categoryIds": [
            4316
          ],
          "discount": "10",
          "isNewOffer": false,
          "specialOfferContent": null,
          "CreatedDate": "27/05/2018 12:47:42",
          "UpdatedDate": "11/12/2019 08:35:55",
          "isPreview": false,
          "isFeatured": false
        },
        "Id": 22184,
        "CreateDate": "2018-05-27T12:47:42",
        "OfferDatefromTo": {
          "validFrom": "2013-10-17T00:00:00",
          "validTo": "2020-12-31T00:00:00"
        },
        "IsPreview": false,
        "BrandId": 6542,
        "CategoryIds": [
          4316
        ],
        "UpdatedDate": "2019-12-11T08:35:55",
        "NotificationTrackID": "00000000-0000-0000-0000-000000000000",
        "NotificationPriority": 0,
        "NotificationPriorityOrderName": null,
        "ContactAddress": "Address",
        "IsPushNotification": false
      }
    ],
    "pageheaderdetail": {
      "title": null,
      "content": null,
      "bannerTitle": null,
      "bannerImage": null,
      "metaTitle": null,
      "metaDescription": null,
      "metaKeywords": null,
      "PageId": null,
      "emailAddress": null,
      "userId": null,
      "preferedName": null
    },
    "status": 1,
    "error": null
  }
}

这是我尝试在 OfferModel.fromJson 方法中解析它的方式：

class OfferModel {
  _ResponseModel _responseModel;


  OfferModel.fromJson(Map<String, dynamic> parsedJson) {
    print(parsedJson['responseModel']['data'].length);
    _responseModel = parsedJson['responseModel'];
    List<_Data> temp = [];
    for(int i=0; i < parsedJson['responseModel']['data'].length; i++) {
      _Data data = _Data(parsedJson['responseModel']['data']._data[i]);
      temp.add(data);
    }
    _responseModel._data = temp;

    print('Responseeeeee= ${_responseModel._data[0]._offer.brandName}');

  }

}

class _ResponseModel {
  List<_Data> _data = [];


}

class _Offer {
  String brandName;
  String brandLogo;
  String id;
  String title;
  String shortDescription;

  _Offer(offer) {
    brandName = offer['brandName'];
    brandLogo = offer['brandLogo'];
    id = offer['id'];
    title = offer['title'];
    shortDescription = offer['shortDescription'];
  }
}

class _Data {
  int id;
  String createDate;
  _Offer _offer;


  _Data(data) {
    id = data['Id'];
    createDate = data['CreateDate'];
    _offer = data['offers'];
  }

  int get iD => id;
  String get create_date => createDate;
}

Answer 1

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

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
   List<OfferModel> dataList = List();
  bool _isLoading = false;

  Future<String> loadFromAssets() async {
    return await rootBundle.loadString('json/parse.json');
  }

  Future loadyourData() async {
    setState(() {
      _isLoading = true;
    });

// this is the local json that i have loaded from the assets folder
// you can make the http call here and else everything later is the same.

    String jsonString = await loadFromAssets();
     final youData = offerModelFromJson(jsonString);
    dataList.add(youData);

    setState(() {
      _isLoading = false;
    });
  }

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

    loadyourData();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
          body: Container(
        child: _isLoading
            ? CircularProgressIndicator()
            : new ListView.builder(
                itemCount: dataList.length,
                itemBuilder: (BuildContext ctxt, int index) {
                  return Column(
                    children: <Widget>[
                      new Text(dataList[index]
                          .responseModel
                          .data[0]
                          .offers
                          .brandName),
                      new Text(dataList[index]
                          .responseModel
                          .data[0]
                          .offers
                          .details[0]
                          .name),
                      new Text(dataList[index].responseModel.status.toString()),
                    ],
                  );
                }),
      )),
    );
  }
}

这是主 ui 页面，数据加载表单是您提供的评估 json

// To parse this JSON data, do
//
//     final offerModel = offerModelFromJson(jsonString);

import 'dart:convert';

OfferModel offerModelFromJson(String str) =>
    OfferModel.fromJson(json.decode(str));

String offerModelToJson(OfferModel data) => json.encode(data.toJson());

class OfferModel {
  ResponseModel responseModel;

  OfferModel({
    this.responseModel,
  });

  factory OfferModel.fromJson(Map<String, dynamic> json) => OfferModel(
        responseModel: ResponseModel.fromJson(json["responseModel"]),
      );

  Map<String, dynamic> toJson() => {
        "responseModel": responseModel.toJson(),
      };
}

class ResponseModel {
  List<Datum> data;
  Pageheaderdetail pageheaderdetail;
  int status;
  dynamic error;

  ResponseModel({
    this.data,
    this.pageheaderdetail,
    this.status,
    this.error,
  });

  factory ResponseModel.fromJson(Map<String, dynamic> json) => ResponseModel(
        data: List<Datum>.from(json["data"].map((x) => Datum.fromJson(x))),
        pageheaderdetail: Pageheaderdetail.fromJson(json["pageheaderdetail"]),
        status: json["status"],
        error: json["error"],
      );

  Map<String, dynamic> toJson() => {
        "data": List<dynamic>.from(data.map((x) => x.toJson())),
        "pageheaderdetail": pageheaderdetail.toJson(),
        "status": status,
        "error": error,
      };
}

class Datum {
  Offers offers;
  int id;
  DateTime createDate;
  Offer offerDatefromTo;
  bool isPreview;
  int brandId;
  List<int> categoryIds;
  DateTime updatedDate;
  String notificationTrackId;
  int notificationPriority;
  dynamic notificationPriorityOrderName;
  String contactAddress;
  bool isPushNotification;

  Datum({
    this.offers,
    this.id,
    this.createDate,
    this.offerDatefromTo,
    this.isPreview,
    this.brandId,
    this.categoryIds,
    this.updatedDate,
    this.notificationTrackId,
    this.notificationPriority,
    this.notificationPriorityOrderName,
    this.contactAddress,
    this.isPushNotification,
  });

  factory Datum.fromJson(Map<String, dynamic> json) => Datum(
        offers: Offers.fromJson(json["offers"]),
        id: json["Id"],
        createDate: DateTime.parse(json["CreateDate"]),
        offerDatefromTo: Offer.fromJson(json["OfferDatefromTo"]),
        isPreview: json["IsPreview"],
        brandId: json["BrandId"],
        categoryIds: List<int>.from(json["CategoryIds"].map((x) => x)),
        updatedDate: DateTime.parse(json["UpdatedDate"]),
        notificationTrackId: json["NotificationTrackID"],
        notificationPriority: json["NotificationPriority"],
        notificationPriorityOrderName: json["NotificationPriorityOrderName"],
        contactAddress: json["ContactAddress"],
        isPushNotification: json["IsPushNotification"],
      );

  Map<String, dynamic> toJson() => {
        "offers": offers.toJson(),
        "Id": id,
        "CreateDate": createDate.toIso8601String(),
        "OfferDatefromTo": offerDatefromTo.toJson(),
        "IsPreview": isPreview,
        "BrandId": brandId,
        "CategoryIds": List<dynamic>.from(categoryIds.map((x) => x)),
        "UpdatedDate": updatedDate.toIso8601String(),
        "NotificationTrackID": notificationTrackId,
        "NotificationPriority": notificationPriority,
        "NotificationPriorityOrderName": notificationPriorityOrderName,
        "ContactAddress": contactAddress,
        "IsPushNotification": isPushNotification,
      };
}

class Offer {
  String validFrom;
  String validTo;

  Offer({
    this.validFrom,
    this.validTo,
  });

  factory Offer.fromJson(Map<String, dynamic> json) => Offer(
        validFrom: json["validFrom"],
        validTo: json["validTo"],
      );

  Map<String, dynamic> toJson() => {
        "validFrom": validFrom,
        "validTo": validTo,
      };
}

class Offers {
  String brandName;
  String brandLogo;
  int id;
  String title;
  String shortDescription;
  dynamic categories;
  dynamic subcategories;
  String offerContactAddress;
  String offerContactWebsite;
  String offerContactTelephone;
  String offerContactEmail;
  dynamic offerContactMobileNumber;
  String aboutThisOffer;
  List<Detail> details;
  List<LocationDetail> locationDetails;
  Offer offerValidity;
  KeywordList keywordList;
  List<String> images;
  dynamic mobileofflineimages;
  List<int> categoryIds;
  String discount;
  bool isNewOffer;
  dynamic specialOfferContent;
  String createdDate;
  String updatedDate;
  bool isPreview;
  bool isFeatured;

  Offers({
    this.brandName,
    this.brandLogo,
    this.id,
    this.title,
    this.shortDescription,
    this.categories,
    this.subcategories,
    this.offerContactAddress,
    this.offerContactWebsite,
    this.offerContactTelephone,
    this.offerContactEmail,
    this.offerContactMobileNumber,
    this.aboutThisOffer,
    this.details,
    this.locationDetails,
    this.offerValidity,
    this.keywordList,
    this.images,
    this.mobileofflineimages,
    this.categoryIds,
    this.discount,
    this.isNewOffer,
    this.specialOfferContent,
    this.createdDate,
    this.updatedDate,
    this.isPreview,
    this.isFeatured,
  });

  factory Offers.fromJson(Map<String, dynamic> json) => Offers(
        brandName: json["brandName"],
        brandLogo: json["brandLogo"],
        id: json["id"],
        title: json["title"],
        shortDescription: json["shortDescription"],
        categories: json["categories"],
        subcategories: json["subcategories"],
        offerContactAddress: json["offerContactAddress"],
        offerContactWebsite: json["offerContactWebsite"],
        offerContactTelephone: json["offerContactTelephone"],
        offerContactEmail: json["offerContactEmail"],
        offerContactMobileNumber: json["offerContactMobileNumber"],
        aboutThisOffer: json["aboutThisOffer"],
        details:
            List<Detail>.from(json["details"].map((x) => Detail.fromJson(x))),
        locationDetails: List<LocationDetail>.from(
            json["locationDetails"].map((x) => LocationDetail.fromJson(x))),
        offerValidity: Offer.fromJson(json["offerValidity"]),
        keywordList: KeywordList.fromJson(json["keywordList"]),
        images: List<String>.from(json["images"].map((x) => x)),
        mobileofflineimages: json["mobileofflineimages"],
        categoryIds: List<int>.from(json["categoryIds"].map((x) => x)),
        discount: json["discount"],
        isNewOffer: json["isNewOffer"],
        specialOfferContent: json["specialOfferContent"],
        createdDate: json["CreatedDate"],
        updatedDate: json["UpdatedDate"],
        isPreview: json["isPreview"],
        isFeatured: json["isFeatured"],
      );

  Map<String, dynamic> toJson() => {
        "brandName": brandName,
        "brandLogo": brandLogo,
        "id": id,
        "title": title,
        "shortDescription": shortDescription,
        "categories": categories,
        "subcategories": subcategories,
        "offerContactAddress": offerContactAddress,
        "offerContactWebsite": offerContactWebsite,
        "offerContactTelephone": offerContactTelephone,
        "offerContactEmail": offerContactEmail,
        "offerContactMobileNumber": offerContactMobileNumber,
        "aboutThisOffer": aboutThisOffer,
        "details": List<dynamic>.from(details.map((x) => x.toJson())),
        "locationDetails":
            List<dynamic>.from(locationDetails.map((x) => x.toJson())),
        "offerValidity": offerValidity.toJson(),
        "keywordList": keywordList.toJson(),
        "images": List<dynamic>.from(images.map((x) => x)),
        "mobileofflineimages": mobileofflineimages,
        "categoryIds": List<dynamic>.from(categoryIds.map((x) => x)),
        "discount": discount,
        "isNewOffer": isNewOffer,
        "specialOfferContent": specialOfferContent,
        "CreatedDate": createdDate,
        "UpdatedDate": updatedDate,
        "isPreview": isPreview,
        "isFeatured": isFeatured,
      };
}

class Detail {
  String type;
  String name;
  String content;

  Detail({
    this.type,
    this.name,
    this.content,
  });

  factory Detail.fromJson(Map<String, dynamic> json) => Detail(
        type: json["type"],
        name: json["name"],
        content: json["content"],
      );

  Map<String, dynamic> toJson() => {
        "type": type,
        "name": name,
        "content": content,
      };
}

class KeywordList {
  List<String> keywords;

  KeywordList({
    this.keywords,
  });

  factory KeywordList.fromJson(Map<String, dynamic> json) => KeywordList(
        keywords: List<String>.from(json["keywords"].map((x) => x)),
      );

  Map<String, dynamic> toJson() => {
        "keywords": List<dynamic>.from(keywords.map((x) => x)),
      };
}

class LocationDetail {
  String latitude;
  String longitude;
  String address;

  LocationDetail({
    this.latitude,
    this.longitude,
    this.address,
  });

  factory LocationDetail.fromJson(Map<String, dynamic> json) => LocationDetail(
        latitude: json["latitude"],
        longitude: json["longitude"],
        address: json["address"],
      );

  Map<String, dynamic> toJson() => {
        "latitude": latitude,
        "longitude": longitude,
        "address": address,
      };
}

class Pageheaderdetail {
  dynamic title;
  dynamic content;
  dynamic bannerTitle;
  dynamic bannerImage;
  dynamic metaTitle;
  dynamic metaDescription;
  dynamic metaKeywords;
  dynamic pageId;
  dynamic emailAddress;
  dynamic userId;
  dynamic preferedName;

  Pageheaderdetail({
    this.title,
    this.content,
    this.bannerTitle,
    this.bannerImage,
    this.metaTitle,
    this.metaDescription,
    this.metaKeywords,
    this.pageId,
    this.emailAddress,
    this.userId,
    this.preferedName,
  });

  factory Pageheaderdetail.fromJson(Map<String, dynamic> json) =>
      Pageheaderdetail(
        title: json["title"],
        content: json["content"],
        bannerTitle: json["bannerTitle"],
        bannerImage: json["bannerImage"],
        metaTitle: json["metaTitle"],
        metaDescription: json["metaDescription"],
        metaKeywords: json["metaKeywords"],
        pageId: json["PageId"],
        emailAddress: json["emailAddress"],
        userId: json["userId"],
        preferedName: json["preferedName"],
      );

  Map<String, dynamic> toJson() => {
        "title": title,
        "content": content,
        "bannerTitle": bannerTitle,
        "bannerImage": bannerImage,
        "metaTitle": metaTitle,
        "metaDescription": metaDescription,
        "metaKeywords": metaKeywords,
        "PageId": pageId,
        "emailAddress": emailAddress,
        "userId": userId,
        "preferedName": preferedName,
      };
}

这是你的 json 数据的模型类

{
    "responseModel": {
        "data": [
            {
                "offers": {
                    "brandName": "Yoga",
                    "brandLogo": "364t3.jpg",
                    "id": 2214,
                    "title": "Up to 40% discount on yoga classes",
                    "shortDescription": "<p>Up to 40% discount </p>",
                    "categories": null,
                    "subcategories": null,
                    "offerContactAddress": "<p>Kolkata</p>",
                    "offerContactWebsite": "http://www.google.com",
                    "offerContactTelephone": "123 456",
                    "offerContactEmail": "abcd@gmail.com",
                    "offerContactMobileNumber": null,
                    "aboutThisOffer": "<p>Yoga is a science of healthy and happy living. </p>",
                    "details": [
                        {
                            "type": "OfferValue",
                            "name": "Offer",
                            "content": "<p>My Content</p>"
                        }
                    ],
                    "locationDetails": [
                        {
                            "latitude": "25.32",
                            "longitude": "55.23",
                            "address": "Kolkata"
                        },
                        {
                            "latitude": "25.1239",
                            "longitude": "55.643",
                            "address": "Mumbai"
                        }
                    ],
                    "offerValidity": {
                        "validFrom": "10/17/2013",
                        "validTo": "12/31/2020"
                    },
                    "keywordList": {
                        "keywords": [
                            "Yoga",
                            "Weight Loss"
                        ]
                    },
                    "images": [
                        "20pic2.jpg",
                        "20pic1.jpg"
                    ],
                    "mobileofflineimages": null,
                    "categoryIds": [
                        4316
                    ],
                    "discount": "10",
                    "isNewOffer": false,
                    "specialOfferContent": null,
                    "CreatedDate": "27/05/2018 12:47:42",
                    "UpdatedDate": "11/12/2019 08:35:55",
                    "isPreview": false,
                    "isFeatured": false
                },
                "Id": 22184,
                "CreateDate": "2018-05-27T12:47:42",
                "OfferDatefromTo": {
                    "validFrom": "2013-10-17T00:00:00",
                    "validTo": "2020-12-31T00:00:00"
                },
                "IsPreview": false,
                "BrandId": 6542,
                "CategoryIds": [
                    4316
                ],
                "UpdatedDate": "2019-12-11T08:35:55",
                "NotificationTrackID": "00000000-0000-0000-0000-000000000000",
                "NotificationPriority": 0,
                "NotificationPriorityOrderName": null,
                "ContactAddress": "Address",
                "IsPushNotification": false
            }
        ],
        "pageheaderdetail": {
            "title": null,
            "content": null,
            "bannerTitle": null,
            "bannerImage": null,
            "metaTitle": null,
            "metaDescription": null,
            "metaKeywords": null,
            "PageId": null,
            "emailAddress": null,
            "userId": null,
            "preferedName": null
        },
        "status": 1,
        "error": null
    }
}

这是你提供的 json，请检查代码并告诉我它是否有效。

Answer 2

我已经在 DartPad 上测试了这段代码，它对我有用：

class OfferModel {
  String brandName;
  String brandLogo;
  int id;
  String title;
  String shortDescription;

  OfferModel({
    this.brandName,
    this.brandLogo,
    this.id,
    this.title,
    this.shortDescription,
  });

  factory OfferModel.fromJson(Map json) {
    return OfferModel(
      brandName: json['brandName'],
      brandLogo: json['brandLogo'],
      id: json['id'],
      title: json['title'],
      shortDescription: json['shortDescription'],
    );
  }
}

class DataModel {
  int id;
  String createDate;
  OfferModel offer;

  DataModel({this.id, this.createDate, this.offer});

  factory DataModel.fromJson(Map json) {
    return DataModel(
        id: json['Id'],
        createDate: json['CreateDate'],
        offer: OfferModel.fromJson(json['offers']));
  }
}

class ResponseModel {
  List<DataModel> data;

  ResponseModel({this.data});

  factory ResponseModel.fromJson(Map json) {
    List<DataModel> datas = [];
    json['responseModel']['data'].forEach((item) => datas.add(DataModel.fromJson(item)));
    return ResponseModel(data: datas);
  }
}

void main() {
  var responseModel = ResponseModel.fromJson(jsonDecode(myJson));
  print('Responseeeeee= ${responseModel.data.first.offer.brandName}');
}