json - 发生异常 : type '_InternalLinkedHashMap' is not a subtype of type 'List' in type cast

Question

您好，我正在学习 flutter 并从 api 获取 json，但是在我的模型中对其进行解码时，出现下面列出的错误。我知道这与我的分页有关，因为定位结果很好，但无法弄清楚我需要做什么来修复分页结果。我尝试了很多教程，但没有运气。谁能指出我正确的方向以解决此问题？提前致谢

错误

Exception occured: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'List<dynamic>' in type cast*

location.dart

class Locations {
  final String id;
  final String name;
  final String street;
  final String city;
  final String state;

  Locations(
    {
      this.id,
      this.name,
      this.street,
      this.city,
      this.state,
    }
  );

  Locations.fromJSON(Map<String, dynamic> json)
    : id = json['id'],
      name = json['name'],
      street = json['street'],
      city = json['city'],
      state = json['state'];
}

class Pagination {
  final int pages;
  final int totalResults;

  Pagination(this.pages, this.totalResults);

  Pagination.fromJSON(Map<String, dynamic> json)
    : pages = json['pages'],
      totalResults = json['count'];
}

class LocationsResponse {
  final List<Locations> results;
  final List<Pagination> pagination;
  final String error;

  LocationsResponse(this.results, this.pagination, this.error);

  LocationsResponse.fromJSON(Map<String, dynamic> json)
    : results = (json["results"] as List).map((i) => new Locations.fromJSON(i)).toList(),
      pagination = (json['pagination'] as List).map((i) => new Pagination.fromJSON(i)).toList(),
      error = "";

  LocationsResponse.withError(String errorValue)
      : results = List(),
        pagination = List(),
        error = errorValue;
}

返回示例

{  
   results:[  
      {  
         id:1,
         name:House,
         street:1234 This Street,
         city:Example City,
         state:Ca      
      }
   ],
   pagination:{  
      count:1,
      pages:0
   }
}

Answer 1

pagination 是 JSONObject 而不是 JSONArray。 像这样更改代码:

 LocationsResponse.fromJSON(Map<String, dynamic> json)
    : results = (json["results"] as List).map((i) => new Locations.fromJSON(i)).toList(),
      pagination = Pagination.fromJSON(json['pagination']),
      error = "";