Use dio in Flutter / Dart

We use dart's built-in HttpClient to call HTTP API:

HttpClient httpClient = HttpClient();
HttpClientRequest request = await httpClient.getUrl(uri);
// ...

But using dio to do so is much easier. If you are Python developer, thinking this as the built-in urllib vs the requests lib. The latter one is much easier to use.

Let's do a quick demo of using thsi dio package.

1, Create a folder named "diotest", then create the pubspec.yaml file:

name: diotest
environment:
  sdk: '>=2.10.0 <3.0.0'

2, Install the dio package:

$ dart pub add dio

3, Create main.dart and write code like this:

import 'package:dio/dio.dart';

void main() async {
  BaseOptions options = BaseOptions(
    baseUrl: "https://httpbin.org",
    connectTimeout: 3000,
    receiveTimeout: 3000,
  );
  Dio dio = Dio(options);
  try {
    Response resp = await dio.get(
      "/get",
      queryParameters: {"search": "dio"},
    );
    print("Response:");
    print("Status:\n${resp.statusCode}");
    print("Header:\n${resp.headers}");
    print("Data:\n${resp.data}");
  } catch (e) {
    print("Exception: $e");
  }
}

All set, now just run it:

$ dart main.dart
Response:
Status:
200
Header:
connection: keep-alive
access-control-allow-credentials: true
date: Fri, 17 Dec 2021 04:50:26 GMT
access-control-allow-origin: *
content-length: 306
content-type: application/json
server: gunicorn/19.9.0

Data:
{args: {search: dio}, headers: {Accept-Encoding: gzip, Host: httpbin.org, User-Agent: Dart/2.14 (dart:io), X-Amzn-Trace-Id: Root=1-61bc1712-57909160379aeca870fa551c}, origin: 67.83.137.85, url: https://httpbin.org/get?search=dio}

For more on sending POST / PUT / DELETE / Upload Files, you can just visit the example page

Reference

• dart package
• dio examples