未处理的异常：类型 'List<int>' 不是类型转换 Flutter http post 请求中类型 'String' 的子类型

如何解决未处理的异常：类型 'List<int>' 不是类型转换 Flutter http post 请求中类型 'String' 的子类型

我正在尝试使用包含对象数组的字段的 Flutter 发送 post 请求，我应该发送一个包含对象的 int (ids) 的列表.. 类似

List<int> theList = [10,20,30,40,50]

但是Flutter不会让我以这种方式发送它返回错误：

Unhandled Exception: type 'List<int>' is not a subtype of type 'String' in type cast Flutter HTTP post request

这是我的代码：

  Future lawyerRegister(LawyerRegisterModel lawyerRegisterModel) async {
    String theUrl = '${baseURL}Lawyer/';

    Client client = Client();
    List<int> lawyerIDImageBytes =
        await File(lawyerRegisterModel.lawyerIDImagePath).readAsBytes();
    String lawyerIDImageBytes64Image = base64Encode(lawyerIDImageBytes);
    List<int> personalImageBytes =
        await File(lawyerRegisterModel.lawyerIDImagePath).readAsBytes();
    String personalImageBytes64Image = base64Encode(personalImageBytes);
    try {
      return client.post(theUrl,headers: {
        'Authorization': 'Token $thetoken',},body: {
        'sections': lawyerRegisterModel.fields,//Error comes from this line,here is where i want to send the array of objects
        'city': lawyerRegisterModel.cityID.toString(),'bio': lawyerRegisterModel.bio,'full_name': lawyerRegisterModel.fullName,'mobile': lawyerRegisterModel.mobile,'lawyer_id': lawyerIDImageBytes64Image,'image': personalImageBytes64Image,}).then((response) {
        print(response.body);
      });
    } catch (e) {
      print(e);
    } finally {
      client.close();
    }
  }

当我尝试更改字段以将其作为字符串发送时

 'sections': lawyerRegisterModel.fields.toString(),

它从后端返回此错误：

Incorrect type. Expected pk value,received str.

解决方法

您可以将 POST 正文编码为 JSON。

return client.post(theUrl,headers: {
        'Authorization': 'Token $theToken',},body: jsonEncode({
        'sections': lawyerRegisterModel.fields,'city': lawyerRegisterModel.cityID.toString(),'bio': lawyerRegisterModel.bio,'full_name': lawyerRegisterModel.fullName,'mobile': lawyerRegisterModel.mobile,'lawyer_id': lawyerIDImageBytes64Image,'image': personalImageBytes64Image,}))

编辑：请注意您需要为 import 'dart:convert' 设置 jsonEncode

,

您可以将 int 列表编码为字符串

import 'dart:convert';


List<int> theList = [10,20,30,40,50];
String encodedList = jsonEncode(theList);