Reference.push失败：第一个参数包含属性“ Questions.code”中的未定义

Question

我一直收到此错误。我正在将数据推送到Firebase。我正在使用离子4

Reference.push失败：第一个参数包含属性'Questions.code'中的未定义

我在下面发布了我的html，.ts和我的界面文件。

当我按下提交时，数据应该存储在firebase中。并且我相信我的界面文件中具有属性“ Question.code”。

这是我的html文件

<ion-content class="home">
 <form
   [formGroup]="form"
   (ngSubmit)="manage(form.value)">
   <ion-list>
       <ion-input
           type="text"
           maxlength="100"
           formControlName="name"  ></ion-input>
   <div class ="thebody"formArrayName="questions">
    <section
       [formGroupName]="i"
       *ngFor="let quest of form.controls.questions.controls; let i = index">
       <ion-item-group>
           <ion-item-divider class="itemdivider">Question no.{{ i + 1 }}</ion-item-divider>
       <ion-item>
             <ion-label floating>Question</ion-label>
             <ion-input
               type="text"
               maxlength="50"
               formControlName="name" [(ngModel)]="questions[i]" ></ion-input>
         </ion-item>


         <!--All the buttons part-->
         <span
         float-right
         ion-button
         icon-left
         clear
         color= "dark"
         *ngIf="form.controls.questions.length> 1"
         (click)="removeInputField(i)">
         <ion-icon md="md-remove-circle"></ion-icon>


       </span>

       <span
       float-right
       ion-button
       icon-left
       clear
       (click)="showOptions()"
       >

       <ion-icon md="md-options"></ion-icon>
       </span>

   </ion-item-group>
 </section>
</div>



<span
  ion-button
   float-left
   icon-left
   clear
   (click)="addNewInputField()">
   <ion-icon md="md-add-circle"color="dark"></ion-icon>
    Add a new question
</span>


       </ion-list>
       <!-- Only allow form to be submitted IF validation criteria for
               input fields has been successfully passed   text-center
           [disabled]="!form.valid"-->
         <button
           ion-button
           block
           margin-top
           color="dark"
           (click)="submitQuiz(questions)">Submit</button>
   </form>
</ion-content>

这是我的.ts文件

import { Component, OnInit } from '@angular/core';


import {FormBuilder, FormArray, FormGroup, Validators } from '@angular/forms';
import { Quiz, Questions } from '../../services/event/quiz.interface';
import {AngularFireList} from 'angularfire2/database'; 
import { AngularFireDatabase} from 'angularfire2/database';
import { ActivatedRoute } from '@angular/router';




@Component({
  selector: 'app-event-create',
  templateUrl: './event-create.page.html',
  styleUrls: ['./event-create.page.scss'],
})
export class EventCreatePage implements OnInit {
  quiz= {} as Quiz;
  questions= {} as Questions;

  questions$: AngularFireList<Questions>;
i = 1;
j=0;
z=0;
public form : FormGroup;

  constructor(private databse: AngularFireDatabase,private _FB: FormBuilder,private route: ActivatedRoute,) {

    this.questions$ = this.databse.list('Questions');

    this.form = this._FB.group({
      name: ['',Validators.required],
      questions :this._FB.array([
        this.initQuestionsField()
      ])

  });
   }

   initQuestionsField(): FormGroup{
    return this._FB.group({
     name : ['',Validators.required]
    });
   }

   addNewInputField():void {
    const control = <FormArray>this.form.controls.questions;
    control.push(this.initQuestionsField());
    this.i=this.i +1;
  }

  removeInputField(i :number):void{
    const control =<FormArray>this.form.controls.questions;
    control.removeAt(i);
  }

  submitQuiz(questions: Questions) {
    this.route.params.subscribe((params) => {
      const code = params.code;
      console.log(code);
      for (let z = 0; z < this.i; z++) {
        console.log(questions[z]);
        this.questions$.push({
          code: code,
          question: questions[z]
        });
      }
    });
  }

  ngOnInit() {
  }

}

这是我的界面文件

export interface Quiz {
    code: String;
  }
  export interface Users {
      email: String;
      password: String;
      nickname: String;
  }
  export interface Questions{
      code: String;
      question: any;
  }