Flutter - 无法通过 http.get 从 api 获取数据

Question

我正在尝试从 Unsplash API 获取数据到我的 Flutter 应用程序，但我仍然收到错误 404。要连接 API，我正在使用 dart:http package v.0.13 。我尝试在 Postman 上使用相同的 Uri，我得到状态码 200，所以 URL 很好（https://api.unsplash.com/photos/random/?client_id=API_KEY）。请检查我的代码。

Future<void> getRandomImage() async {
var res = await http.get(Uri.https('api.unsplash.com',
    '/photos/random/?client_id=API_KEY'));
if (res.statusCode == 200) {
  var decodedData = jsonDecode(res.body);
  print(decodedData);
} else {
  print(res.statusCode);
  throw 'Problem with the get request';
}}

Answer 1

网络服务：

class NetService {
  static Future<T?> getJson<T>(String url, {int okCode = 200}) {
    return http.get(Uri.parse(url))
      .then((response) {
        if (response.statusCode == okCode) {
          return jsonDecode(response.body) as T;
        }
        PrintService.showDataNotOK(response);
        return null;
      })
      .catchError((err) => PrintService.showError(err));
  }
}

主要：

import 'dart:async';

import 'package:_samples2/networking.dart';

class Unsplash {
  static const _apiKey = '11111111111111111111111111111';
  static const _url = 'https://api.unsplash.com/photos/random/?client_id=$_apiKey';

  static FutureOr<void> fetchRandomImage() async {
    print('Start fetching...\n');
    await NetService.getJson<Map<String, dynamic>>(_url)
      .then((response) => print(response))
      .whenComplete(() => print('\nFetching done!'));
  }
}

void main(List<String> args) async {
  await Unsplash.fetchRandomImage();
  print('Done!');
}

结果：

Start fetching...

{id: 6qUn2lQF9A4, created_at: 2021-03-06T08:38:48-05:00, updated_at: 2021-03-12T01:39:06-05:00, promoted_at: 2021-03-07T04:56:18-05:00, width: 6000, height: 4000, color: #735959, blur_hash: LJEVHCRk0LWXM_oJt7ozNGWBs:of, description: null, alt_description: woman with blonde hair holding a pen, urls: {raw: https://images.unsplash.com/photo-1615037486765-e96acbe87231?ixid=MnwyMTQ0MjV8MHwxfHJhbmRvbXx8fHx8fHx8fDE2MTU1Njg5NTQ&ixlib=rb-1.2.1, full: https://images.unsplash.com/photo-1615037486765-e96acbe87231?crop=entropy&cs=srgb&fm=jpg&ixid=MnwyMTQ0MjV8MHwxfHJhbmRvbXx8fHx8fHx8fDE2MTU1Njg5NTQ&ixlib=rb-1.2.1&q=85, regular: https://images.unsplash.com/photo-1615037486765-e96acbe87231?crop=entropy&cs=tinysrgb&fit=max&fm=jpg&ixid=MnwyMTQ0MjV8MHwxfHJhbmRvbXx8fHx8fHx8fDE2MTU1Njg5NTQ&ixlib=rb-1.2.1&q=80&w=1080, small: https://images.unsplash.com/photo-1615037486765-e96acbe87231?crop=entropy&cs=tinysrgb&fit=max&fm=jpg&ixid=MnwyMTQ0MjV8MHwxfHJhbmRvbXx8fHx8fHx8fDE2MTU1Njg5NTQ&ixlib=rb-1.2.1&q=80&w=400, thumb: https://images.unsplash.com/photo-1615037486765-e96acbe87231?crop=entropy&cs=tinysrgb&fit=max&fm=jpg&ixid=MnwyMTQ0MjV8MHwxfHJhbmRvbXx8fHx8fHx8fDE2MTU1Njg5NTQ&ixlib=rb-1.2.1&q=80&w=200}, links: {self: https://api.unsplash.com/photos/6qUn2lQF9A4, html: https://unsplash.com/photos/6qUn2lQF9A4, download: https://unsplash.com/photos/6qUn2lQF9A4/download, download_location: https://api.unsplash.com/photos/6qUn2lQF9A4/download?ixid=MnwyMTQ0MjV8MHwxfHJhbmRvbXx8fHx8fHx8fDE2MTU1Njg5NTQ}, categories: [], likes: 13, liked_by_user: false, current_user_collections: [], sponsorship: null, user: {id: PZ7vHHbEDBs, updated_at: 2021-03-12T05:45:35-05:00, username: victoriapriessnitz, name: Victoria Priessnitz, first_name: Victoria, last_name: Priessnitz, twitter_username: null, portfolio_url: https://www.instagram.com/victoriapriessnitz_photo/, bio: www.priessnitzstudio.cz
https://www.instagram.com/priessnitzstudio/
, location: Czech Republic, links: {self: https://api.unsplash.com/users/victoriapriessnitz, html: https://unsplash.com/@victoriapriessnitz, photos: https://api.unsplash.com/users/victoriapriessnitz/photos, likes: https://api.unsplash.com/users/victoriapriessnitz/likes, portfolio: https://api.unsplash.com/users/victoriapriessnitz/portfolio, following: https://api.unsplash.com/users/victoriapriessnitz/following, followers: https://api.unsplash.com/users/victoriapriessnitz/followers}, profile_image: {small: https://images.unsplash.com/profile-1588431995209-edb1b4743462image?ixlib=rb-1.2.1&q=80&fm=jpg&crop=faces&cs=tinysrgb&fit=crop&h=32&w=32, medium: https://images.unsplash.com/profile-1588431995209-edb1b4743462image?ixlib=rb-1.2.1&q=80&fm=jpg&crop=faces&cs=tinysrgb&fit=crop&h=64&w=64, large: https://images.unsplash.com/profile-1588431995209-edb1b4743462image?ixlib=rb-1.2.1&q=80&fm=jpg&crop=faces&cs=tinysrgb&fit=crop&h=128&w=128}, instagram_username:  victoriapriessnitz_photography, total_collections: 0, total_likes: 4, total_photos: 266, accepted_tos: true, for_hire: false}, exif: {make: null, model: null, exposure_time: null, aperture: null, focal_length: null, iso: null}, location: {title: null, name: null, city: null, country: null, position: {latitude: null, longitude: null}}, views: 91851, downloads: 939}

Fetching done!
Done!