Why I'm getting this exception: _TypeError (type 'List' is not a subtype of type 'Map<String, dynamic>')

this is my http method:

    import 'dart:convert';
import 'package:arzenafees/model/areaguide.dart';
import 'package:http/http.dart' as http;

Future<Areaguide> fetcharea() async {
  final response = await http.get(
      Uri.parse('https://arz-e-nafees.nafeessolutions.com/public/api/view'));
  if (response.statusCode == 200) {
    return Areaguide.fromJson(jsonDecode(response.body));
  } else {
    throw Exception('Unexpected error occured!');
  }
}

this is my model class which I created using quicktype.io:

import 'dart:convert';

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

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

class Areaguide {
  Areaguide({
    required this.propertyImage,
    required this.propertyTitle,
    required this.locationCity,
    required this.locationArea,
    required this.propertyDescription,
    required this.propertyPrice,
  });

  String propertyImage;
  String propertyTitle;
  String locationCity;
  String locationArea;
  String propertyDescription;
  String propertyPrice;

  factory Areaguide.fromJson(Map<String, dynamic> json) => Areaguide(
        propertyImage: json["property_image"],
        propertyTitle: json["property_title"],
        locationCity: json["location_city"],
        locationArea: json["location_area"],
        propertyDescription: json["property_description"],
        propertyPrice: json["property_price"],
      );

  Map<String, dynamic> toJson() => {
        "property_image": propertyImage,
        "property_title": propertyTitle,
        "location_city": locationCity,
        "location_area": locationArea,
        "property_description": propertyDescription,
        "property_price": propertyPrice,
      };
}

Note: please provide answer which applies to all related question, do not limits it to this specific problem, which might help others with type errors.

CodePudding user response：

Try this.

static Future<List<Areaguide>?> fetcharea() async {
       
        final response = await http.get(
            Uri.parse('https://arz-e-nafees.nafeessolutions.com/public/api/view));
                if (response.statusCode == 200) {
                  List<Areaguide> property = (json.decode(response.body)).map<Areaguide>((m)=> Areaguide.fromJson(m)).toList();
                  return property;
            } else {
            throw Exception('Unexpected error occured!');
            }
        }

CodePudding user response：

Instead of writing fromJson and toJson methods, you can use json_serializable library (https://docs.flutter.dev/development/data-and-backend/json). In short: after installing the dependency you just define your model and run a command. It works also for nested models.