如何改进此指令以显示带有mat-error的自定义错误

<mat-form-field>
  <input matInput formControlName="myControl">
  <mat-error *ngIf="myForm.get('myControl').hasError('required')">This field is required</mat-error>
</mat-form-field>

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

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

  ngOnInit() {
    this.myForm = new FormGroup({
      myControl: new FormControl('', Validators.required)
    });
  }
}

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';

@NgModule({
  declarations: [MyComponentComponent],
  imports: [
    CommonModule,
    FormsModule,
    ReactiveFormsModule
  ]
})
export class MyModule { }