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首页 > 解决方案 > 未处理的异常：键入“列表”' 不是类型转换中类型 'String' 的子类型

http - 未处理的异常：键入“列表”' 不是类型转换中类型 'String' 的子类型

问题描述

我正在尝试在我的 api 中发布一个字符串列表。

以下是我的网络代码

class DashboardFeeCountApiProvider implements DashboardFeeCountSource {
  @override
  Future<DashboardFeeCountModel> getDashboardFees(String type, String userId,
      String yearId, List<String> feeCategoryId) async {
    final response = await http.post(DASHBOARD_FEE_URL, body: {
      "type": "1",
      "userid": userId,
      "yearId": yearId,
      "fee_cat_id": feeCategoryId
    });
    DashboardFeeCountModel dashboardFeeCountModel =
        standardSerializers.deserializeWith(
            DashboardFeeCountModel.serializer, json.decode(response.body));
    return dashboardFeeCountModel;
  }
}

以下是我的集团代码

fetchDashboardFee(String type, String userId, String yearId,
      List<String> feeCategoryId) async {
    final dashboardFee =
        await _repository.getDashboardFees(type, userId, yearId, feeCategoryId);
    _dashboardFeeCount.sink.add(dashboardFee);
  }

所以在我的主屏幕上，我正在做如下的事情

class _DashboardListState extends State<DashboardList> {
  DashboardFeesBloc dashboardFeesBloc;
  List<String> categoryListIds = List<String>();

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    categoryListIds.add("0");
    dashboardFeesBloc = DashboardFeesProvider.of(context);
    //TODO remov hardcoded values
    dashboardFeesBloc.fetchDashboardFee("1","1483", "2", categoryListIds);

  }.....

但是每当我提出请求时，我都会收到以下错误

VERBOSE-2:ui_dart_state.cc(148)] Unhandled Exception: type 'List<String>' is not a subtype of type 'String' in type cast
#0      CastMap.forEach.<anonymous closure> (dart:_internal/cast.dart:286:25)
#1      __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.forEach (dart:collection/runtime/libcompact_hash.dart:367:8)
#2      CastMap.forEach (dart:_internal/cast.dart:285:13)
#3      mapToQuery (package:http/src/utils.dart:17:7)
#4      Request.bodyFields= (package:http/src/request.dart:128:17)
#5      BaseClient._sendUnstreamed (package:http/src/base_client.dart:163:17)
<asynchronous suspension>
#6      BaseClient.post (package:http/src/base_client.dart:54:7)
#7      post.<anonymous closure> (package:http/http.dart:70:16)
#8      _withClient (package:http/http.dart:166:20)
<asynchronous suspension>
#9      post (package:http/http.dart:69:5)
#10     DashboardFeeCountApiProvider.getDashboardFees (package:dice_admin/resources/dashboard/dashboard_fee_count/dashboard_fee_count_api_provider.d<…&gt;

我也尝试将我的列表转换为字符串，但我不断收到错误。从 Api 角度来看没有问题，因为它在 Postman 中正常工作。

我想我不能直接在请求参数中传递 List 我猜这是导致问题的原因。

标签： httpdartflutter

解决方案

在带有 http 的 Fluter 应用程序中：

body:{"array":dataArray.join(' ') // transform your List in String}

在服务器端应用程序中：

req.body.array.split(' ') // transform your String in initial Array

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