如何解决未处理的异常：类型 '_InternalLinkedHashMap<String, dynamic>' 不是类型 'String' 的子类型

Question

String baseUrl = 'https://api.mapbox.com/geocoding/v5/mapbox.places';
String accessToken = dotenv.env['MAPBOX_ACCESS_TOKEN']!;

Dio _dio = Dio();

Future getReverseGeocodingGivenLatLngUsingMapbox(LatLng latLng) async {
  String query = '${latLng.longitude},${latLng.latitude}';
  String url = '$baseUrl/$query.json?access_token=$accessToken';
  url = Uri.parse(url).toString();
  print(url);
  try {
    _dio.options.contentType = Headers.jsonContentType;
    final responseData = await _dio.get(url);
    return responseData.data;
  } catch (e) {
    final errorMessage = DioExceptions.fromDioError(e as DioError).toString();
    debugPrint(errorMessage);
  }
}

下面使用上面的函数

Future<Map> getParsedReverseGeocoding(LatLng latLng) async {
  var response =
  json.decode(await getReverseGeocodingGivenLatLngUsingMapbox(latLng));
  Map feature = response['features'][0];
  Map revGeocode = {
    'name': feature['text'],
    'address': feature['place_name'].split('${feature['text']}, ')[1],
    'place': feature['place_name'],
    'location': latLng
  };
  return revGeocode;
}

然后在下面使用上面的函数：

void initializeLocationAndSave() async {
   
   LatLng currentLocation = getCurrentLatLngFromSharedPrefs();
   String currentAddress =
    (await getParsedReverseGeocoding(currentLocation))['place'];
}

 LatLng getCurrentLatLngFromSharedPrefs() {

    return LatLng(sharedPreferences.getDouble('latitude')!,   
    sharedPreferences.getDouble('longitude')!);
 }

但是，我无法检索 currentAddress 值。显示以下错误：

Unhandled Exception: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'String'

我哪里错了？我正在使用代码 from here by following the youtube tutorial

Answer 1

Dio自动解码，去掉json.decode即可。

The default value is JSON, dio will parse response string to json object automatically when the content-type of response is 'application/json'.

如何解决未处理的异常：类型 '_InternalLinkedHashMap<String, dynamic>' 不是类型 'String' 的子类型

How to solve Unhandled Exception: type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 'String'

flutter

dart

mapbox

mapbox-android