业务场景：页面中包含多个独立的下拉框，需要同时加载下拉列表。 import {Observable} from 'rxjs/Observable'; import 'rxjs/add/observable/forkJoin'; import 'rxjs/add/observable/merge'; import 'rxjs/add/observable/zip'; let http1 = this.http.get('url'); let http2 = this.http.get('url'); let http3 = ...
