Question

因此，我对Ionic-angular开发非常陌生，现在我只是想在home.ts文件中定义一个函数，并在home.html文件中调用它，以便在FirebaseDB中进行基本的创建。这是我的home.html文件：

home.html
    <ion-header>
  <ion-navbar>
    <ion-title>
      Ionic Blank
    </ion-title>
    <ion-buttons end>
        <button ion-button icon-only (click)="addCourse()">
          <ion-icon name="add"></ion-icon>
        </button>
      </ion-buttons>
  </ion-navbar>

</ion-header>

<ion-content padding>
</ion-content>

这是我的home.ts文件

home.ts
    import { Component } from '@angular/core';
import { NavController, AlertController } from 'ionic-angular';
import { AngularFireDatabase, AngularFireList } from 'angularfire2/database';
import { Observable } from '../../../node_modules/rxjs';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {
  songsList: AngularFireList<any>;
  songs: Observable<any>;

  constructor(public navCtrl: NavController, public afDB: AngularFireDatabase, public alertCtrl: AlertController) {
    this.songsList = this.afDB.list('/songs');
    this.songs = this.songsList.valueChanges();

    function addCourse(){
      let prompt = this.alertCtrl.create({
        title: 'Course Name',
        message: "Enter the Course Code",
        inputs: [
          {
            name: 'title',
            placeholder: 'Title'
          },
        ],
        buttons: [
          {
            text: 'Cancel',
            handler: data => {
              console.log('Cancelled');
            }
          },
          {
            text: 'Save',
            handler: data => {
              const newSongRef = this.songs.push({});

              newSongRef.set({
                id: newSongRef.key,
                title: data.title
              });
            }
          }
        ]
      });
      prompt.present();
    }
  }


    }

从function addCourse(){...}删除声明'function'时出现错误，但在网站上收到此错误

_co.addCourse() is not a function. (In '_co.addCourse()','_co.addCourse() is undefined)

首先，我认为这是因为我应该在构造函数之外定义函数，但是随后如何调用数据库或警报控制器？

感谢帮助！

Answer 1

您不应该具有关键字function，它应该在构造函数之外，将其更改为

constructor(public navCtrl: NavController, public afDB: AngularFireDatabase, public alertCtrl: AlertController) {
}

addCourse(){
}

_co.addCourse（）不是函数-即使我在ts文件中定义了它

1 个答案: