如何显示来自角度验证器的错误？

<form [formGroup]="registerForm">
  <div>
    <label for="email">Email</label>
    <input id="email" formControlName="email">
    <div *ngIf="registerForm.get('email').invalid && (registerForm.get('email').dirty || registerForm.get('email').touched)">
      <div *ngIf="registerForm.get('email').errors.required">Email is required.</div>
      <div *ngIf="registerForm.get('email').errors.email">Invalid email format.</div>
    </div>
  </div>
  <!-- 其他表单字段 -->
</form>

<form #registerForm="ngForm">
  <div>
    <label for="email">Email</label>
    <input id="email" name="email" [(ngModel)]="user.email" required email>
    <div *ngIf="registerForm.controls['email'].invalid && (registerForm.controls['email'].dirty || registerForm.controls['email'].touched)">
      <div *ngIf="registerForm.controls['email'].errors?.required">Email is required.</div>
      <div *ngforEach="let error of registerForm.controls['email'].errors | keyvalue">{{error.key}}: {{error.value}}</div>
    </div>
  </div>
  <!-- 其他表单字段 -->
</form>