使用动态formArray Angular 7中的自定义验证器比较两个值

import { AbstractControl, ValidatorFn } from '@angular/forms';

export function compareValuesValidator(controlName1: string, controlName2: string): ValidatorFn {
  return (control: AbstractControl): { [key: string]: any } | null => {
    const value1 = control.get(controlName1)?.value;
    const value2 = control.get(controlName2)?.value;

    if (value1 !== value2) {
      return { compareValues: true };
    }

    return null;
  };
}

import { FormGroup, FormBuilder } from '@angular/forms';
import { compareValuesValidator } from './compare-values.validator';

@Component({
  selector: 'app-my-form',
  templateUrl: './my-form.component.html',
  styleUrls: ['./my-form.component.css']
})
export class MyFormComponent implements OnInit {
  form: FormGroup;

  constructor(private formBuilder: FormBuilder) { }

  ngOnInit() {
    this.form = this.formBuilder.group({
      passwords: this.formBuilder.array([
        this.formBuilder.control(''),
        this.formBuilder.control('')
      ], { validators: compareValuesValidator('password', 'confirmPassword') })
    });
  }
}

<form [formGroup]="form">
  <div formArrayName="passwords">
    <div *ngFor="let password of form.get('passwords').controls; let i = index">
      <input type="password" [formControlName]="i">
    </div>
  </div>
  <div *ngIf="form.get('passwords').errors?.compareValues">
    Passwords do not match.
  </div>
</form>