问角材自定义输入验证信息未用垫子显示

EN

  get errorState(): boolean {
    const touched=!!this.ngControl?.touched;
    if (touched!=this.touched)
    {
      this.touched=touched;
      this.stateChanges.next();
    }
    return (this.parts.invalid || !!this.ngControl?.invalid) && this.touched;
  }

<button type="button" mat-button matStepperNext 
   (click)="form.markAllAsTouched()" >Next</button>

export class MyTelInput
  implements ControlValueAccessor, MatFormFieldControl<MyTel>, OnDestroy
{
.
.
.
touched = true; //change from false to true
.
.
}