Angular 6-访问嵌套的formArray

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

@Component({
  selector: 'app-example',
  templateUrl: './example.component.html',
  styleUrls: ['./example.component.css']
})
export class ExampleComponent {
  myForm: FormGroup;

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

  get nestedArray(): FormArray {
    return this.myForm.get('nestedArray') as FormArray;
  }

  addNestedItem() {
    this.nestedArray.push(this.fb.control(''));
  }

  removeNestedItem(index: number) {
    this.nestedArray.removeAt(index);
  }
}

<form [formGroup]="myForm">
  <div formArrayName="nestedArray">
    <div *ngFor="let item of nestedArray.controls; let i = index" [formGroupName]="i">
      <input type="text" formControlName="nestedControl">
      <button (click)="removeNestedItem(i)">Remove</button>
    </div>
  </div>
  <button (click)="addNestedItem()">Add Item</button>
</form>