如何编写依赖于Angular2中当前组件属性值的自定义表单验证器(模型驱动)

function customValidator(control: AbstractControl): ValidationErrors | null {
  // 获取当前组件属性值
  const currentValue = control.value;
  
  // 根据属性值进行验证逻辑
  if (currentValue === 'example') {
    return { customError: true };
  }
  
  // 验证通过时返回 null
  return null;
}

import { Validators } from '@angular/forms';

@Component({
  // 组件配置
})
export class MyComponent {
  myForm: FormGroup;
  
  constructor(private fb: FormBuilder) {
    this.myForm = this.fb.group({
      myField: ['', Validators.compose([Validators.required, customValidator])]
    });
  }
}

<form [formGroup]="myForm">
  <input type="text" formControlName="myField">
  <div *ngIf="myForm.get('myField').errors?.required">该字段为必填项</div>
  <div *ngIf="myForm.get('myField').errors?.customError">自定义错误消息</div>
</form>