Angular2如何获取表单的错误消息?

Angular2 how to get errors message of form?

我想在组件功能中获取错误消息,而不是在模板中显示它们:

<p [hidden]="!name.control.errors.required" *ngIf="name?.control?.errors?.required">name is required</p>

如何获取组件功能中表单的错误信息?

如果您有权访问与输入关联的控件,则可以执行相同的操作:

@Component({
  template: `
    <form>
      <input [ngFormControl]="control"/>
    </form>
    <div (click)="showError()">Show error</div>
  `
})
export class MyComponent {
  constructor() {
    this.control = new Control('', Validators.required);
  }

  showError() {
    if (this.control.errors.required) {
      // Have the required error
    }
  }
}