我如何從 Flutter 中的 Api 的嵌套對象中獲取價值？

Question

我正在做一個項目，我的問題與 api 中的嵌套對象有關。 我想從我的數據對象中獲取消息，但它無法訪問，而且我的模型類沒有提供任何關於消息的信息。 其實我想從這一行“數據”：“{“消息”：“Saim12345與你確認約會日期為15-06-2022下午06:20在線視頻咨詢”}”，。 只有消息值如“ Saim12345 已與您確認約會日期為 15-06-2022 下午 06:20 在線視頻咨詢”

我已經嘗試 JsonEcode 來獲取它的索引，但效果不佳，我也創建了單獨的數據類並創建了字符串消息，但是如果有人可以幫助我，請盡快回復我

進一步這是我的模型類

List<NotificationModel> notificationModelFromJson(String str) => List<NotificationModel>.from(json.decode(str).map((x) => NotificationModel.fromJson(x)));

String notificationModelToJson(List<NotificationModel> data) => json.encode(List<dynamic>.from(data.map((x) => x.toJson())));

class NotificationModel {
  NotificationModel({
    this.id,
    this.type,
    this.notifiableType,
    this.notifiableId,
    this.data,
    this.readAt,
    this.createdAt,
    this.updatedAt,
  });

  double id;
  String type;
  String notifiableType;
  int notifiableId;
  String data;
  DateTime readAt;
  DateTime createdAt;
  DateTime updatedAt;

  factory NotificationModel.fromJson(Map<String, dynamic> json) => NotificationModel(
    id: json["id"].toDouble(),
    type: json["type"],
    notifiableType: json["notifiable_type"],
    notifiableId: json["notifiable_id"],
    data: json["data"],
    readAt: DateTime.parse(json["read_at"]),
    createdAt: DateTime.parse(json["created_at"]),
    updatedAt: DateTime.parse(json["updated_at"]),
  );

  Map<String, dynamic> toJson() => {
    "id": id,
    "type": type,
    "notifiable_type": notifiableType,
    "notifiable_id": notifiableId,
    "data": data,
    "read_at": readAt.toIso8601String(),
    "created_at": createdAt.toString(),
    "updated_at": updatedAt.toString(),
  };
}

這是我的課

class PatientNotification extends StatefulWidget {
  final int notificationModelId;
  const PatientNotification({Key key, this.notificationModelId}) : super(key: key);


  @override
  State<PatientNotification> createState() => _PatientNotificationState();
}

class _PatientNotificationState extends State<PatientNotification> {
  NotificationModel notification;

  List<NotificationModel> notificationModelList = [];
  bool loading = true;
  Map mapResponse;


  

  void getNotifications() async {
    notificationModelList = [];
    Network network = new Network();
    var response = await network.getData("/notifications");


    log(response.body);


   

    if (response.statusCode == 200) {
      var json = cnv.jsonDecode(response.body);


      // try{
      if (json != null) {
        json.forEach((element) {
          notificationModelList.add(new NotificationModel.fromJson(element));
        });
        print(notificationModelList.length);
      }
      //   }catch(e){
      //     // log(e);
      // }

    }
    setState(() {
      notificationModelList = notificationModelList;
      // datalist=datalist;

      loading = false;
    });
  }


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


  @override
  Widget build(BuildContext context) {
    return Scaffold(
        body: SafeArea(
          child: Column(
            children: [
              Row(
                mainAxisAlignment: MainAxisAlignment.start,
                children: [
                  GestureDetector(
                    onTap: () {
                      Navigator.pop(context);
                    },
                    child: Icon(
                      Icons.arrow_back_rounded,
                      color: AppColor.primary,
                      //size: .0,
                      // semanticLabel: 'Text to announce in accessibility modes',
                    ),
                  ),
                  TextButton(
                    onPressed: getNotifications,
                    child: Text(
                      "Notifications",
                      textAlign: TextAlign.left,
                      style: TextStyle(
                          fontSize: 24,
                          letterSpacing: 0.7,
                          color: Colors.black),
                    ),
                  ),
                ],
              ),
              SizedBox(
                height: 10,
              ),
              Expanded(child: SingleChildScrollView(
                  child: Container(
                      height: MediaQuery
                          .of(context)
                          .size
                          .height * 0.8,
                      child: loading ? AppWidgetsCard.getProgressIndicator()
                          : notificationModelList.isEmpty
                          ? AppWidgetsCard.getEmptyCard('Notification') :
                      ListView.builder(
                          itemCount: notificationModelList.length,
                          itemBuilder: (context, index) {
                            NotificationModel data = notificationModelList[index];

                            String dateFormate = DateFormat()
                                .add_yMMMEd()
                                .format(DateTime.parse(
                                data.createdAt.toString()));
                            String time = DateFormat()
                                .add_jm()
                                .format(DateTime.parse(
                                data.createdAt.toString()));
                            return Container(
                              decoration: BoxDecoration(
                                borderRadius: BorderRadius.circular(15),
                              ),
                              height: 110,
                              width: MediaQuery
                                  .of(context)
                                  .size
                                  .width,
                              padding: EdgeInsets.symmetric(
                                  horizontal: 1, vertical: 5),
                              child: Card(
                                elevation: 5,
                                shape: RoundedRectangleBorder(
                                  borderRadius:
                                  BorderRadius.circular(15.0),
                                ),
                                child: Row(
                                  children: [
                                    Container(
                                      height: 100,
                                      width: 100,
                                      decoration: BoxDecoration(
                                          borderRadius:
                                          BorderRadius.only(
                                            bottomLeft:
                                            Radius.circular(15),
                                            topLeft:
                                            Radius.circular(15),
                                            // topRight:
                                            //     Radius.circular(15),
                                            // bottomRight:
                                            //     Radius.circular(15),
                                          ),
                             
                                          image: DecorationImage(
                                              image: NetworkImage(
                                                  'https://emedz.net/images/doctors/male-avi.jpg'),
                                              fit: BoxFit.fill
                                          )

                                      ),

                                    ),
                                    Expanded(
                                      child: Padding(
                                        padding:
                                        const EdgeInsets.all(8.0),
                                        child: Row(
                                          mainAxisAlignment:
                                          MainAxisAlignment
                                              .spaceBetween,
                                          children: [
                                            Expanded(
                                              child: Column(
                                                mainAxisAlignment:
                                                MainAxisAlignment
                                                    .spaceBetween,
                                                crossAxisAlignment:
                                                CrossAxisAlignment
                                                    .start,
                                                children: [
                                                  Text(
                                                    data.data,
                                                    style: TextStyle(
                                                        fontSize: 12,
                                                        color: Colors
                                                            .black,
                                                        fontWeight:
                                                        FontWeight
                                                            .bold),
                                                  ),
                                                  Expanded(
                                                      child:
                                                      SizedBox()),
                                                  Text('',
                                                    style: TextStyle(
                                                        fontSize: 10,
                                                        color: Colors
                                                            .blue),
                                                  ),
                                                  
                                                  Text(
                                                    '$dateFormate at $time  ',
                                                    maxLines: 2,
                                                    style: TextStyle(
                                                      fontSize: 14,
                                                    ),
                                                  ),
                                                ],
                                              ),
                                            ),
                                            
                                          ],
                                        ),
                                      ),
                                    ),
                                  ],
                                ),
                              ),
                            );
                          }))

              ),
              )
            ],
          ),
        ));
  }
}

Answer 1

不幸的是，您的數據是字符串，您必須將其轉換為 json 並解析它，所以這樣做

        dataJson = data.substring(1, data.length-1); //it will remove double quotes from string

然后使用......將此json發送到數據模型

   final dataModel = dataModelFromJson(dataJson);// this line where you pass dataJson

下面是您的數據模型類.......

   DataModel dataModelFromJson(String str) => 
   DataModel.fromJson(json.decode(str));

   String dataModelToJson(DataModel data) => json.encode(data.toJson());

   class DataModel {
   DataModel({
    @required this.message,
   });

   String message;

   factory DataModel.fromJson(Map<String, dynamic> json) => DataModel(
      message: json["message"],
   );

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

Answer 2

我已經解決了它，例如

並打印了我的信息

這是我想要Saim12345 與您確認約會日期為 15-06-2022 下午 06:20 在線視頻咨詢的結果

  if (json != null) {
        json.forEach((element) {

          Map obj= element;
           message=obj['data'];
          message = message.replaceRange(0, 12, '');
          message = message.replaceRange((message.length-2), message.length, '');
       print(message);
          // var klk= cnv.jsonDecode(plm);
          print(message.toString());
          notificationModelList.add(new NotificationModel.fromJson(element));
        });
        print(notificationModelList.length);
      }