如何在没有formGroup的情况下控制formArray？

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

@Component({
  selector: 'app-example',
  template: `
    <div>
      <button (click)="addControl()">Add Control</button>
      <button (click)="removeControl(i)" *ngFor="let control of formArray.controls; let i = index">Remove Control {{ i }}</button>
      <div *ngFor="let control of formArray.controls; let i = index">
        <input [formControl]="control" placeholder="Control {{ i }}">
      </div>
    </div>
  `,
})
export class ExampleComponent {
  formArray: FormArray = new FormArray([]);

  addControl() {
    const control = new FormControl('');
    this.formArray.push(control);
  }

  removeControl(index: number) {
    this.formArray.removeAt(index);
  }
}