无法在Angular中获取以前检查过的表单的值

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

@Component({
  selector: 'app-form',
  template: `
    <form #myForm="ngForm">
      <input type="text" name="name" [(ngModel)]="name" required>
      <input type="email" name="email" [(ngModel)]="email" required>
      <button (click)="submitForm()">Submit</button>
    </form>
  `,
})
export class FormComponent {
  myForm: FormGroup;
  name: string;
  email: string;

  constructor() {
    this.myForm = new FormGroup({
      name: new FormControl(),
      email: new FormControl(),
    });
  }

  submitForm() {
    console.log(this.myForm.value);
  }
}

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

@Component({
  selector: 'app-form',
  template: `
    <form #myForm="ngForm">
      <input type="text" name="name" [(ngModel)]="name" required>
      <input type="email" name="email" [(ngModel)]="email" required>
      <button (click)="submitForm()">Submit</button>
    </form>
  `,
})
export class FormComponent {
  myForm: FormGroup;
  name: string;
  email: string;
  previousFormValues: any;

  constructor() {
    this.myForm = new FormGroup({
      name: new FormControl(),
      email: new FormControl(),
    });

    this.myForm.valueChanges.subscribe((value) => {
      this.previousFormValues = value;
    });
  }

  submitForm() {
    console.log(this.previousFormValues);
  }
}