json - 如何将 json 列表传递给 Flutter 中的 http 请求(post)主体？

Question

我有一些对象将由用户填写在表单中。我将这些对象解析为 json 并将该 json 添加到列表中以传递请求正文。但我不能这样做。

  incrementListPaymentSlipes(PaymentSlipes objPayment) async {
    objPayment.name = "Douglas";
    objPayment.personalId = "00000000000";
    Map<String, dynamic> json = objPayment.toJson();
    listPaymentSlipes.add(jsonEncode(json));
  }

var response = await http.post(url, body: {
"payment_slips": listPaymentSlipes,
}

正确正文示例:

"payment_slips": [
    {      
      "personal_id": "01888728680",
      "name": "Fulano da Silva"
    }
  ]

 {"error":"'{{personal_id: 00000000000, name: Douglas}}' é invalido como 'payment_slips'","code":"payment_slips_invalid"}```

Answer 1

你可以用一种非常简单的方式来做到这一点。创建 payment.dart 文件并复制粘贴以下代码类。

class PaymentList {
PaymentList(this.payments);

List<Payment> payments;

Map<String, dynamic> toJson() => <String, dynamic>{
    'payment_slips': payments,
  };
}

class Payment {
Payment({this.name, this.personalId});

String name;
String personalId;

Map<String, dynamic> toJson() => <String, dynamic>{
    'personal_id': personalId,
    'name': name,
  };
}

现在您可以使用以下代码将其转换为所需的 json 格式。例如我正在创建一个虚拟列表:

final PaymentList paymentList =
    PaymentList(List<Payment>.generate(2, (int index) {
  return Payment(name: 'Person $index', personalId: '$index');
}));
final String requestBody = json.encoder.convert(paymentList);

requestBody 变量将具有如下 json 字符串:

  {"payment_slips": [
    {
        "personal_id": "0",
        "name": "Person 0"
    },
    {
        "personal_id": "1",
        "name": "Person 1"
    }
  ]}

现在你可以调用 api 了:

var response = await http.post(url, body: requestBody}

注意:请导入以下包，访问json需要:

import 'dart:convert';