ionic 登陆 注销 （ts格式）

在输入帐号与密码点击登陆时若是成功，登陆页面隐藏，显示出登陆成功后的用户中心，而后点击用户中心的注销，弹出登陆页面

首先引入ViewController

import {NavController,LoadingController,ToastController,ModalController,ViewController} from 'ionic-angular';

constructor(private navCtrl: NavController, private loadingCtrl: LoadingController,private toastCtrl: ToastController,public modalCtrl: ModalController,public viewCtrl: ViewController) {
  	this.navCtrl=navCtrl;
}

login(){
     /* var localStorage = {
              username:'',
              Logined:'',
            }*/
    if(this.user.username==''){
      let toast=this.toastCtrl.create({
      message:"请填写用户名",
      duration:3000,
      position:"middle"
      });
      toast.onDidDismiss(() =>{
        console.log("has dismissed");
        });
      toast.present();
      }else if(this.user.username!=='' && this.user.userpassword=="1"){
        //设置localStorage 的 username 与Logined,在ts中只能这样设置
        localStorage.setItem("username", this.user.username);
        localStorage.setItem("Logined", "true");

        let loading = this.loadingCtrl.create({
        content: 'Please wait...'
      });
     若是显示loading,下面的this.viewCtrl.dismiss(this.user.username);无效 不知是什么缘由
      // loading.present();
       
       //this.viewCtrl.dismiss();
       setTimeout(() => {
         
          //alert(this.viewCtrl);
         // 页面消失时传入用户的用户名，用于用户中心的头像切换
          this.viewCtrl.dismiss(this.user.username);
          
          loading.dismiss();
          
           }, 1000);
       

      } else if(this.user.username!=='' && this.user.userpassword!=="1"){

        let toast=this.toastCtrl.create({
          message:"登陆失败，密码错误",
          duration:3000,
          position:"middle"
          });
          toast.present();
      }

  }

用户中心页面

import {Component} from '@angular/core';
import {NavController,LoadingController,AlertController,ToastController,ModalController,ViewController } from 'ionic-angular';
import {ImagePicker} from 'ionic-native';
import {ContactPage} from '../contact/contact';


@Component({
  templateUrl: 'build/pages/contact/usercenter.html'
})
export class UserCenter {
	public user={
       username : '',
       userpassword :'' ,
       headface:'images/1.png'  
  }
  constructor(private navCtrl: NavController, private loadingCtrl: LoadingController, private alertCtrl: AlertController, private toastCtrl: ToastController,public modalCtrl: ModalController,public viewCtrl: ViewController) {
  	//this.navCtrl=navCtrl;
   // this.viewCtrl=viewCtrl;

    if(localStorage.getItem("Logined") == "true"){
      //已经登陆的状态，不跳转，显示用户信息便可
      this.user.headface = 'images/'+localStorage.getItem("username")+'.png' 
    } else {
       let modal = this.modalCtrl.create(ContactPage);
       modal.onDidDismiss(data => {
       this.user.headface= 'images/'+ data +'.png' 
   });
        modal.present();
    }
  }
  logout(){
    localStorage.setItem("username","");
    localStorage.setItem("Logined", "");
    let modal = this.modalCtrl.create(ContactPage);
     modal.onDidDismiss(data =>{
        this.user.headface= 'images/'+ data +'.png' 
        });
    modal.present();
  }

 
   

}