为什么 Cors 阻止我对我的 Api 的请求？ [复制]

Question

我正在开发一个项目，我需要访问我开发的 Api

const endpoint = 'localhost:3000/api/v1/';
const httpOptions = {
  headers: new HttpHeaders({
    'Content-Type': 'application/json',
  }),
};

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

  private extractData(res: Response) {
    let body = res;
    return body || {};
  }

  getRequest(id: String): Observable<Request> {
    return this.http.get<Request>(endpoint + 'request/' + id, httpOptions);
  }

我已经授予权限以便我可以访问它，但我收到此错误

ccess to XMLHttpRequest at 'localhost:3000/api/v1/request/5ec3fbd84fe7bf4aa8d48b39' from origin 'http://localhost:4200' has been blocked by CORS policy: Cross origin requests are only supported for protocol schemes: http, data, chrome, chrome-extension, https.

这里是权限：

app.use(
  cors({
    credentials: true,
    origin: "http://localhost:4200",
  })
);

找到了解决办法。端点应该是'http://localhost:3000/api/v1/'

Answer 1

错误消息提到请求的无效方案。尝试将“http”添加到您的端点

const endpoint = 'http://localhost:3000/api/v1/';