问为什么我不能将我的http请求存储在我的列表中？颤振/飞镖
EN

Stack Overflow用户

提问于 2022-10-13 03:47:46

回答 1查看 31关注 0票数 0

你好，我正在尝试将我的请求保存到我的列表中，但是它说未处理的异常:类型'String‘不是'index’的'int‘类型的子类型。

这是我的班：

class Evsebill {
  final String serial;
  final double value;
  final double vat;
  final double total;
  final int energy;
 const Evsebill({
    required this.serial,
    required this.value,
    required this.vat,
    required this.total,
    required this.energy
  });
  factory Evsebill.fromJson(Map<String, dynamic> json) {
    return Evsebill(
      serial: json['serial'] as String,
      value: json['value']as double,
      vat: json['vat']as double,
      total: json['total']as double,
      energy: json['energy']as int,
    );
  }
}

以下是我的要求：

List<Evsebill> parseBills(String responseBody) {
    final parsed = jsonDecode(responseBody)["results"]["cardBillsTotal"].cast<Map<String, dynamic>>();

    return parsed.map<Evsebill>((json) => Evsebill.fromJson(json)).toList();
  }

Future<List<Evsebill>> fetch() async {
    String? token = await this.storage.read(key: "token");
    Map<String, String> headers = {
      "Content-Type": "application/json",
      "Accept": "application/json",
      "Authorization": "Bearer " + (token ?? ""),
    };
    final response = await http.get(Uri.parse(
        this.serverIP + ':' + this.serverPort +
            '/user/contractedChargeTransactionsList?page=1&limit=10&year=eq:2022'),
        headers: headers);
    if (response.statusCode == 200) {
      setState(() {
        print(response.body);
        cardBills = jsonDecode(response.body)["results"]["cardBillsTotal"] as List;
        var result = cardBills.map((e) => Evsebill.fromJson(e)).toList();
      });
      return cardBills.map((e) => Evsebill.fromJson(e)).toList();
    }
    else{
      throw Exception('Failed to load Bills');
    }
  }

这是我的印刷品(response.body)；

I/flutter (19587): {"results":[{"firstName":"Î˜Ï‰Î¼Î¬Ï‚","lastName":"Î Î±Ï€Î±ÏŠÏ‰Î¬Î½Î½Î¿Ï…","userID":238,"month":5,"year":2022,"cardBillsTotal":[{"serial":"884221337251","value":1.0450,"vat":0.2508,"total":1.2958,"energy":0}]},{"firstName":"Î˜Ï‰Î¼Î¬Ï‚","lastName":"Î Î±Ï€Î±ÏŠÏ‰Î¬Î½Î½Î¿Ï…","userID":238,"month":6,"year":2022,"cardBillsTotal":[{"serial":"884221337251","value":3.4034,"vat":0.8168,"total":4.2202,"energy":0}]},{"firstName":"Î˜Ï‰Î¼Î¬Ï‚","lastName":"Î Î±Ï€Î±ÏŠÏ‰Î¬Î½Î½Î¿Ï…","userID":238,"month":7,"year":2022,"cardBillsTotal":[{"serial":"884221337251","value":2.0900,"vat":0.5016,"total":2.5916,"energy":0}]},{"firstName":"Î˜Ï‰Î¼Î¬Ï‚","lastName":"Î Î±Ï€Î±ÏŠÏ‰Î¬Î½Î½Î¿Ï…","userID":238,"month":5,"year":2022,"cardBillsTotal":[{"serial":"941368618045","value":2.2884,"vat":0.5492,"total":2.8376,"energy":0}]},{"firstName":"Î˜Ï‰Î¼Î¬Ï‚","lastName":"Î Î±Ï€Î±ÏŠÏ‰Î¬Î½Î½Î¿Ï…","

flutter

dart

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回答 1

Stack Overflow用户

回答已采纳

发布于 2022-10-13 04:04:05

您应该迭代您的http reponse，因为它是一个列表，并且首先您应该访问每个元素。所以不是这些，

cardBills = jsonDecode(response.body)["results"]["cardBillsTotal"] as List;
        //cardBillsTotal = jsonDecode(response.body)["cardBillsTotal"] as List;
        month = jsonDecode(response.body)['month'];
        userid = jsonDecode(response.body)['userID'];

你应该有这样的东西：

final response = jsonDecode(response.body)["results"];
(response as List<dynamic>).forEach((e) {

        month = e['month'];
        userid = e['userID'];

        //and so on
        })
        .toList()