如何在Ionic 4中将动态输入字段添加到数组中？

import { Component } from '@angular/core';
import { FormBuilder, FormGroup, FormArray } from '@angular/forms';

@Component({
  selector: 'app-dynamic-form',
  templateUrl: './dynamic-form.page.html',
  styleUrls: ['./dynamic-form.page.scss'],
})
export class DynamicFormPage {
  dynamicForm: FormGroup;

  constructor(private fb: FormBuilder) {
    this.dynamicForm = this.fb.group({
      fields: this.fb.array([])
    });
  }

  get fields() {
    return this.dynamicForm.get('fields') as FormArray;
  }

  addField() {
    const field = this.fb.control('');
    this.fields.push(field);
  }

  onSubmit() {
    console.log(this.dynamicForm.value);
  }
}

<form [formGroup]="dynamicForm" (ngSubmit)="onSubmit()">
  <div formArrayName="fields">
    <div *ngFor="let field of fields.controls; let i = index" [formGroupName]="i">
      <input formControlName="field" placeholder="Field {{i + 1}}">
    </div>
  </div>
  <button type="button" (click)="addField()">Add Field</button>
  <button type="submit">Submit</button>
</form>