加载

Question

我被困在这里几个小时，需要帮助。如何进行http请求，以便在加载时可以使用它。目前使用以下代码，视图会加载，但服务器的响应不会到来，必须等待几秒才能使其可用。

的src /应用程序/ example.ts

 import { MyApp } from 'app.component';
    import {Injectable} from '@angular/core';
    import {Http} from '@angular/http';
    import 'rxjs/Rx';

    @Injectable()
    export class ExampleApis{

        http: any;
        requestURL: string;

        constructor( http:Http ){
            this.http = http;
            this.requestURL = 'https://www.example.com/api';
        }

        locations(){
            return this.http.get( this.requestURL + '/locations/?format=json').map( result => result.json() );
        }

    }

的src /页/地方对入住/地方对stay.ts 的

import { Component } from '@angular/core';
import { NavController, NavParams } from 'ionic-angular';
import { ExampleApis } from '../../app/apis';

@Component({
  selector: 'page-places-to-stay',
  templateUrl: 'places-to-stay.html'
})
export class PlacesToStayPage {

  locationsList: any;

  constructor(public navCtrl: NavController, public navParams: NavParams, public ExampleApis:ExampleApis) {
    this.regions();
  }

  locations(){
    this.ExampleApis.locations().subscribe( response => {
      this.locationsList = response.results;
    });
  }

}