两个输入字段之间的Angular2+共享验证

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

@Component({
  selector: 'app-shared-validation',
  templateUrl: './shared-validation.component.html',
  styleUrls: ['./shared-validation.component.css']
})
export class SharedValidationComponent implements OnInit {
  sharedForm: FormGroup;

  constructor(private formBuilder: FormBuilder) { }

  ngOnInit() {
    this.sharedForm = this.formBuilder.group({
      password: ['', Validators.required],
      confirmPassword: ['', Validators.required]
    }, { validator: this.passwordMatchValidator });
  }

  passwordMatchValidator(formGroup: FormGroup) {
    const password = formGroup.get('password').value;
    const confirmPassword = formGroup.get('confirmPassword').value;

    if (password !== confirmPassword) {
      formGroup.get('confirmPassword').setErrors({ mismatch: true });
    } else {
      formGroup.get('confirmPassword').setErrors(null);
    }
  }
}