在电子邮件验证Angular FormControl中，对象可能为'null‘

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

@Component({
  selector: 'app-email-validation',
  template: `
    <input type="email" [formControl]="emailControl">
    <div *ngIf="emailControl.invalid && emailControl.touched">
      <div *ngIf="emailControl.errors.required">
        Email is required.
      </div>
      <div *ngIf="emailControl.errors.email">
        Invalid email format.
      </div>
    </div>
  `
})
export class EmailValidationComponent {
  emailControl: FormControl;

  constructor() {
    this.emailControl = new FormControl(null, [Validators.required, Validators.email]);
  }
}