How to send parameters with GET request in Flutter using Dio or http

Question

I am trying to send a GET request to a back-end server with some parameters, and I have been getting the error:

DioError [DioErrorType.RESPONSE]: Http status error [500]

The parameters I am sending contains a boolean value and a double too. How can I successfully make this request. I have tried so many answers on Stack Overflow but none worked for me. Below is my code snippet:

Future<Converter> currencyConverter() async {
  String convertURL = baseURL + 'convert/currency/';
  String auth = await localpref.getString('access');

  //  FormData formData = new FormData.fromMap({
  //    "switch": _switch,
  //    "s_currency": senderCurrencyVal,
  //    "r_currency": recieverCurrencyVal,
  //    "amount": amount
  //  });

  Map<String, dynamic> payload = {
    "switch": _switch, //boool
    "s_currency": senderCurrencyVal, // string
    "r_currency": recieverCurrencyVal, // string
    "amount": amount  //double
  };
  try {
    var res = await dio.get(
      convertURL,
      //data: formData,
      queryParameters: payload,
      options: Options(
        followRedirects: false,
        validateStatus: (status) {
          return status < 500;
        },
        headers: {
          "accept": "*/*",
          "Authorization": "Bearer $auth",
          "Content-Type": "application/x-www-form-urlencoded"
        }
      )
    );

    if (res.statusCode >= 200 && res.statusCode <= 250) {
      print("Transfer Succeed");
      var respBody = res.data;

      Converter converter = converterFromJson(res.data);
      print(converter.result);
      return converter;
    } else {
      print(res);
      print("Else not successful");
    }
  } catch (e) {
    print(e);
  }
}

Note: that am not in charge of the backend and I am made to know it was developed with Djangom also I have tried both dio.get and dio.request but I got the same result, formdata doesn't work with GET when using Dio.

This request works well in postman.

I would appreciate your help.

Did you tried hitting same url in postman with same parameters ? is it working as expected there ? — Naveen Rao
– Naveen Rao, Commented Aug 9, 2020 at 10:08
Code seems fine. Is this the only request which is not working fine in your project ? — Naveen Rao
– Naveen Rao, Commented Aug 9, 2020 at 11:40
yes , my post and patch works fine and even get without parameter also works fine — Onalo Joseph
– Onalo Joseph, Commented Aug 9, 2020 at 15:12

Rishabh Sharma · Accepted Answer · 2025-07-24 06:52:23Z

1

Remove the below Header from the request and then try.

"Content-Type": "application/x-www-form-urlencoded"

It tells the backend that you are sending data in Form format.

answered Jul 24 at 6:52

Rishabh Sharma

2781 gold badge5 silver badges17 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

king mort · Accepted Answer · 2020-08-09 11:49:06Z

0

Check this out how to fix it Data not showing in list in flutter.

I use http directly for any get.. Also check out https://app.quicktype.io/ to quickly create decoder classes. To use it copy the response from postman here and it will generate a class for you in Dart.

answered Aug 9, 2020 at 11:49

king mort

1,47310 silver badges12 bronze badges

6 Comments

Onalo Joseph Over a year ago

I created a class initially but it was always call on NULL as the api call does not return anything

king mort Over a year ago

Also check out the url... There might be a / missing .. when you used concat

Onalo Joseph Over a year ago

i have done that, in fact the URL works fine without parameters, its when i add parameters , that i have that issue

king mort Over a year ago

Could you share the full link and sample fields i can try run it

king mort Over a year ago

Wait... To send data to receive response you have to use post() that's in http

|

Collectives™ on Stack Overflow

How to send parameters with GET request in Flutter using Dio or http

2 Answers 2

Comments

6 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

6 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related