Why I do not get response using Dio in flutter?答案

【问题标题】：Why I do not get response using Dio in flutter?Why I do not get response using Dio in flutter?
【发布时间】：2022-12-27 05:40:26
【问题描述】：

I am new to dio and I tried to create login function, here is my dio.post code

Future<LoginModel> loginUser(LoginPost data, String method) async {
try {
  final response = await _dio.post(
    'api/users/v1/login/$method',
    data: json.encode(data.toJson(method)),
    options: Options(
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded',
        'Authorization': 'Basic ${base64Encode(
          utf8.encode('$clientId:$clientSecret'),
        )}',
      },
    ),
  );
  LoginModel model = LoginModel.fromJson(json.decode(response.data));
  print(model.success);
  return model;
} catch (error, stacktrace) {
  _printError(error, stacktrace);
  return LoginModel.withError(false, '', '$error', 0);
}
}

and the program only run onRequest Function, the onResponse function is not run by the program. The url, auth, body, etc. are already correct, and I tried using Postman, and the endpoint works. Does anyone know why the program does not receive a response?

【问题讨论】：

Not 1005 sure, but you are sending a Content-Type as form urlencoded but the body data as JSON. You can try changing the Content-Type to application/json and see if that works.
its still not work
Update the question showing a working Postman request.
@RichardHeap already
Very basic question, but, could you reach the API from the device's browser? It's a mobile app? If it's a desktop app on osx, does it has internet permission?

标签： flutter dio

【解决方案1】：

To send data in the application/json format (default for dio)

dio.post(
  '/info', 
  data: {'id': 5},
);

To send data in the application/x-www-form-urlencoded format

dio.post(
  '/info',
  data: {'id': 5},
  options: Options(contentType: Headers.formUrlEncodedContentType),
);

【讨论】：

still no response receive
What is response.statusCode and response.data? Print out right after post call.
I already tried to print it, but it doesn't display
@ParamaArtha you got ans because i have facing same issue

【解决方案2】：

This code certainly gets a response - and works in dartpad, so try it there. (Of course the response is 401, as I don't have the credentials.)

import 'dart:convert';

import 'package:http/http.dart' as http;

void main() async {
  final auth = base64.encode(utf8.encode('cid:secret'));
  final r = await http.post(
    Uri.https('api.komplekku.com', 'core/api/users/v1/login/email'),
    headers: {
      'authorization': 'Basic $auth',
    },
    body: {
      'email': 'foo',
      'password': 'bar',
    },
  );

  print(r.statusCode);
  print(r.body);
}

【讨论】：

【解决方案3】：

If you are using a custom interceptor and using v4+ of dio, remember to call handler.next(..); or .resolve(..) or .reject(..) depending on the method you are overwriting and how you are proceeding in your specific case.

i.e. for intercepting onRequest it would look as this:

dio.interceptors.add(InterceptorsWrapper(onRequest: (options, handler) {
  if (token != null) {
    options.headers['Authorization'] = 'Bearer ${token!}';
  }
  return handler.next(options);
}));

【讨论】：