Question

问题是我想在警报（按钮）中创建一个事件，我想让它移动到另一个页面，这个按钮不再存在于HTML中，因为我无法创建（点击）功能当我运行它时，不要给我任何提供程序错误＆＃34;没有NavController的提供程序＆＃34;。我尝试了另一种选择

我使用了ViewChild并从@angular/core中导入了它制作@viewChild('myApp')并将此#myApp添加到ion-nav
在课堂上定义navCtrl: NavController。

在构造函数中，我添加了public push: Push，但它无法读取它。在这段时间里它给了我＆＃34;无法读取属性＆＃39; navCtrl＆＃39; of null＆＃34;。

import { Component }                                       from '@angular/core';
import { Platform, Alert, AlertController, NavController } from 'ionic-angular';
import { StatusBar }                                       from '@ionic-native/status-bar';
import { SplashScreen }                                    from '@ionic-native/splash-screen';
import   firebase                                          from 'firebase';
import { FirebaseProvider }                                from '../providers/firebase/firebase';
import { ViewProvider }                                    from '../providers/view/view';

//pages
import { OpenPage } from '../pages/open/open';
import { AcceptOrderPage } from '../pages/accept-order/accept-order';

@Component({
  templateUrl: 'app.html'
})

 export class MyApp {
  rootPage = OpenPage;
  public marginClass:any="normal";
  public available:boolean=true;
  public orderId:string;
  public alert: Alert;

  constructor(platform: Platform, statusBar: StatusBar, splashScreen:
   SplashScreen, public fb: FirebaseProvider,
   public view: ViewProvider, private alertCtrl: AlertController, public 
   navCtrl: NavController) {
    platform.ready().then(() => {
     if (platform.is('ios')){
      this.marginClass="iosMargin"
     }
   statusBar.styleDefault();
   splashScreen.hide();
  });
    var config = {
      apiKey: "AIzaSyDbn0bLyNh4emJXjVAKb_BsOyH7ahiY-3U",
      authDomain: "cat-drivers.firebaseapp.com",
      databaseURL: "https://cat-drivers.firebaseio.com",
      projectId: "cat-drivers",
      storageBucket: "cat-drivers.appspot.com",
      messagingSenderId: "444330551162"
    };
    firebase.initializeApp(config);

    var starCountRef = 
     firebase.database().ref('drivers/'+this.orderId+'/Orders');
     starCountRef.on('value', function(snapshot) {
       let alert = alertCtrl.create({
         title: 'لديك طلب جديد؟',
          buttons: [
         {
          text: 'رفض',
          role: 'cancel',
          handler: () => {
            console.log('Cancel clicked');
          }
         },
         {
          text: 'قبول',
          handler: () => {
            console.log('Buy clicked');
            navCtrl.push(AcceptOrderPage);
          }
         }
       ]
     });
     alert.present();
  });
 }
    sendData(x){
      this.view.localGet("uid").then((uid)=>{
      this.fb.setData('drivers/'+uid+'/outOfService/',x)})
    }

    toggleState(item){
     this.available=!this.available;
      // console.log(this.available)
     } 
  }

Answer 1

请检查此代码：

var starCountRef = 
 firebase.database().ref('drivers/'+this.orderId+'/Orders');
var _that=this;
 starCountRef.on('value', function(snapshot) {
   let alert = alertCtrl.create({
     title: 'لديك طلب جديد؟',
      buttons: [
     {
      text: 'رفض',
      role: 'cancel',
      handler: () => {
        console.log('Cancel clicked');
      }
     },
     {
      text: 'قبول',
      handler: () => {
        console.log('Buy clicked');
        _that.navCtrl.push(AcceptOrderPage);
      }
     }
   ]
 });
 alert.present();

无法阅读属性＆＃39; navCtrl＆＃39;无离子3

1 个答案: