ionic3 Loading组件的用法

import { LoadingController } from 'ionic-angular';

@Component({
  selector: 'page-contact',
  templateUrl: 'contact.html'
})
export class ContactPage {

  constructor(public loadingCtrl: LoadingController) {

  }
  showFull(){
    //创建loading窗口，模拟3秒后登录成功，loading消失
    let loader = this.loadingCtrl.create({
      content: "加载中...",
      spinner: 'crescent',
      duration: 3000
    });
    loader.present();

  }