[使用Angular [duplicate]访问Flickr API时出现CORS错误

Question

此问题已经在这里有了答案：

• Flickr JSON returning error in JavaScript cross domain2个答案
• Flickr API call with XMLHttpRequest not working1个答案

我正在使用Angular应用程序，在该应用程序中，我使用Flickr API获得了相册和照片的列表。以下是我创建的用于使用Flickr API的服务]

import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';
import { GlobalsService } from './globals.service';
import * as Rx from 'rxjs';

interface Response {
  photosets: PhotoSets;
}

interface PhotoSets {
  page: number;
  pages: number;
  photoset: PhotoSet[];
  length: number;
}

interface PhotoSet {
  id: string;
  description: String;
  title: String;
}

interface String {
  _content: string;
}

interface PhotoSetByIds {
  photoset: PhotoSetById;
}

interface PhotoSetById {
  id: string;
  owner: string;
  ownername: string;
  page: number;
  pages: number;
  per_page: number;
  perpage: number;
  photo: Photo[];
  primary: string;
  title: string;
  total: string;
}

interface Photo {
  length: number;
  farm: number;
  id: string;
  isfamily: number;
  isfriend: number;
  ispramy: string;
  ispublic: number;
  secret: string;
  server: string;
  title: string;
}

@Injectable({
  providedIn: 'root'
})
export class FlickrServiceService {
  constructor(private http: HttpClient, private globals: GlobalsService) {
  }

  getPhotoSets() {
    return this.http.get<Response>(
      'https://api.flickr.com/services/rest/?method=flickr.photosets.getList&api_key=' +
        this.globals.apiKey +
        '&user_id=' +
        this.globals.userId +
        '&format=json&nojsoncallback=1'
    );
  }

  getPhotos(photosetId: any) {
    return this.http.get<PhotoSetByIds>(
      'https://api.flickr.com/services/rest/?method=flickr.photosets.getPhotos&api_key=' +
        this.globals.apiKey +
        '&photoset_id=' +
        photosetId +
        '&user_id=' +
        this.globals.userId +
        '&format=json&nojsoncallback=1'
    );
  }
}

事实是，当我尝试获得某物时，出现以下CORS错误：

从https://api.flickr.com/services/rest/?method=flickr.photosets.getList&api_key= ＆[user_id =对XMLHttpRequest的访问＆format = json＆nojsoncallback = 1'已被CORS策略阻止：CORS策略不允许请求标头字段授权-飞行前响应中的Control-Allow-Headers。core.js：4002错误HttpErrorResponse {标题：HttpHeaders，状态：0，statusText：“未知错误”，url：“http://localhost:4200... ser_id = 170538248 @ N08＆format = json＆nojsoncallback = 1”，好的：否，...}

我仍然不知道如何解决这个问题。有什么帮助吗？谢谢！

Answer 1

在app.module.ts中导入HttpClientModule，HttpClientJsonpModule

https://api.flickr.com/services/rest/?method=flick

在FlickrService中，您应该使用jsoncallback而不是nojsoncallback。

import { HttpClientModule, HttpClientJsonpModule } from '@angular/common/http';

@NgModule({
  imports: [HttpClientJsonpModule, HttpClientModule]
})
export class AppModule { }

最后在您的组件中，

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Injectable()
export class PhotoService {

imagesUrl = `https://api.flickr.com/services/....../format=json&jsoncallback=JSONP_CALLBACK`;

  constructor(private http: HttpClient) { }

  getPhotos() {
    return  this.http.jsonp(this.imagesUrl, 'JSONP_CALLBACK');
  }

}

希望这会对您有所帮助。