如何使用Dio包在Flutter中以formdata形式发送数组？

Question

我想发送一个带有包含 JSON 数组的复杂 JSON 对象的文件。我该怎么做？

我想发送这种FormData。 这是我的实现方式：

final data = {
  "id": 60,
  "first_name": "Amit",
  "last_name": "Sharma",
  "email": "[email protected]",
  "phone_no": "1111111111",
  "addr": "Lko",
  "status": "VERIFIED",
  "total_funds": 0,
  "bankDetails": [
    {"name": "ASD", "acc": "123"},
    {"name": "ASDFG", "acc": "1234"}
  ]
};
if (file != null) {
  data['pic'] =
      MultipartFile.fromFileSync(file.path, filename: 'profile_image');
}
final formData = FormData.fromMap(data);

final formData = FormData.fromMap(data);

final res = await _dio
    .post(
      '$kBaseUrl$kUploadPlanterStory',
      options: Options(
        headers: headers,
        contentType: Headers.formUrlEncodedContentType,
      ),
      data: formData,
    )
    .catchError((e) => throw getFailure(e));

print(res);

}

Answer 1

https://github.com/flutterchina/dio/issues/1155#issuecomment-842492719

另一种方法是使用

ListFormat.multiCompatible

中的

FormData

参数。

我相信这将适用于嵌套数组，而无需改变你的身体结构，编码或添加

[]

到键：例如

FormData.fromMap(data, ListFormat.multiCompatible); // <-- add this

Answer 2

目前您正在使用

urlEncoded

来编码整个

data

地图，这不是您想要的。如果您想使用不同的序列化方法对请求的特定部分进行编码，则必须手动执行：

final data = {
  // urlEncoded fields
  // ...
  "bankDetails": jsonEncode([
    {"name": "ASD", "acc": "123"},
  ]),
};

//...
data: FormData.fromMap(data)

Answer 3

记住在密钥后面添加“[]”。以表单数据发送数组的最简单方法：

FormData formData = new FormData.fromMap({
  "name": "Max",
  "location": "Paris",
  "age": 21,
  "image[]": [1,2,3],
});

Response response = await dio.post(
  //"/upload",
  "http://143.110.244.110/radius/frontuser/eventsubmitbutton",
  data: formData,
  onSendProgress: (received, total) {
    if (total != -1) {
      print((received / total * 100).toStringAsFixed(0) + '%');
    }
  },
);

Answer 4

final dio = Dio();
dio.options.headers = {
  'Accept': 'application/json',
  'Content-Type': 'multipart/form-data',      
  };

FormData formData = new FormData();
formData = FormData.fromMap({
"[bankDetails][]": [ {"name": "ASD", "acc": "123"},
{"name": "ASDFG", "acc": "1234"} ] });
final responseJson = await dio.post(
    
    url,
    data: formData,
  );

Answer 5

all the above are not right i will explain you how you can do it 

  Future<void> postPropertyAPI(BuildContext context, String projectColonyName) async {
    var typeOfProperty = "";
    if(widget.type == AppStrings.plots){
      typeOfProperty = plotTypeProperty;
    }else if(widget.type == AppStrings.commercialSpace){
      typeOfProperty = commercialTypeProperty;
    }else if(widget.type == AppStrings.flatHouseVilla){
      typeOfProperty = flatHouseTypeProperty;
    }
    Loader.ProgressloadingDialog(context, true);
    try {
      const url = Urls.postPropertyUrl;
      var formData = FormData.fromMap({
        "user_id": userID,
        "calony_name": projectColonyName,
        "type_of_property": typeOfProperty,
        // "location[0]": location,
        "address": propertyAddressController.text,
        "width": widthController.text,
        "length": lengthController.text,
        "totalarea": totalAreaController.text,
        "facing": facing,
        "open_side": openSide,
        "transaction_type": transactionType,
        "possession_status": possessionStatus,
        "expected_price": expectedPriceController.text,
        "price_per_square": pricePerSqFtController.text,
        // "aminities": selectedAmenitiesList,
        "description_details": descriptionController.text,
        "buildup_area": superBuildupAreaController.text,
        "floor_no": totalNoOfFloorsController.text,
        "your_space_in_which_floor": floor,
        "furnished_status": furnished,
        "floor_no": noOfFloor,
        "flat_size": flatSize,
      });
      formData.fields.add(MapEntry("location[]", location));
      selectedAmenitiesList.forEach((amenity) {
        formData.fields.add(MapEntry("aminities[]", amenity));
      });
      final responseDio = await Dio().post(url,data: formData,);
      Loader.ProgressloadingDialog(context, false);
      if (responseDio.statusCode == 200) {
        print(url);

        Map<String, dynamic> map = (responseDio.data as Map).cast<String, dynamic>();
        PostPropertyModel response = PostPropertyModel.fromJson(map);

        Utilities().toast(response.message);
        if (response.status == true) {
          Navigator.of(context).pop();
          setState(() {});
        }
      }

    } catch (e) {
      Loader.ProgressloadingDialog(context, false);
      Utilities().toast('error: $e');
    }
    return;
  }
i want to send location and aminities in array format so dont need any changes in anywhere just do it like
formData.fields.add(MapEntry("location[]", location));
selectedAmenitiesList.forEach((amenity) {
        formData.fields.add(MapEntry("aminities[]", amenity));
      });
    for example selectedAmenitiesList is List<String> selectedAmenitiesList = ["one", "two", "three", "four"] so all are string and MapEntry() is exept only string as a socond args so one more thing you can do like 
        formData.fields.add(MapEntry("aminities[]", amenity.toString()));