Angular Form自定义验证数据

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

// 自定义验证器函数
function customValidator(control: FormControl) {
  const value = control.value;
  if (value && value.length < 6) {
    return { 'customError': '密码长度不能少于6位' };
  }
  return null;
}

@Component({
  selector: 'app-form',
  template: `
    <form [formGroup]="myForm">
      <input type="password" formControlName="password">
      <div *ngIf="myForm.get('password').errors?.customError">
        {{ myForm.get('password').errors.customError }}
      </div>
    </form>
  `,
})
export class FormComponent {
  myForm: FormGroup;

  constructor() {
    this.myForm = new FormGroup({
      password: new FormControl('', [Validators.required, customValidator])
    });
  }
}