mat-error 不显示错误消息 角度 5

问题是即使我将字段留空并移至另一个字段，也不会显示错误消息。我无法找到我在这里做错了什么。任何帮助将不胜感激。如果我在 onFormValuesChanged() 上放置断点，它永远不会到达断点。我尝试过在构造函数内移动表单的构建部分，但没有任何影响。我不确定当字段值更改时是否触发表单的值更改事件

角度版本：- 5.2.1

HTML 代码

   <div>
    <form [formGroup]="formPersonalRecord">
    <mat-input-container class="full-width-input">
    <input matInput placeholder="First Name" formControlname="firstName">
      <mat-error *ngIf="formErrors.firstName.required">
      Please provide name.
      </mat-error>
     </mat-input-container>
     <mat-input-container class="full-width-input">
     <input matInput placeholder="Last Name" formControlname="lastName">
     </mat-input-container>
      <mat-input-container class="full-width-input">
      <input matInput placeholder="Father's Name" formControlname="fatherName">   
     </mat-input-container>
     <mat-input-container class="full-width-input">
      <input matInput placeholder="Email" formControlname="email">
       <mat-error *ngIf="formErrors.email.required">
        Please provide a email name.
       </mat-error>
     </mat-input-container>
    </form>
    </div>

组件.cs

import { Component, OnInit } from '@angular/core';
import { EmployeePersonalRecord } from '../employee/employee-personal-record';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';
import { fuseAnimations } from '../../core/animations';
import { HrService } from '../hr.service';



@Component({
  // tslint:disable-next-line:component-selector
  selector: 'app-add-employee',
  templateUrl: './add-employee.component.html',
  styleUrls: ['./add-employee.component.scss'],
  animations: fuseAnimations
})

export class AddEmployeeComponent implements OnInit {

  employeePersonalRecord:   EmployeePersonalRecord     = {} as EmployeePersonalRecord;
  public formPersonalRecord:       FormGroup;
  formErrors: any;
  constructor(private builder: FormBuilder,
    private service: HrService) {
  }

  onFormValuesChanged()
  {
    for ( const field in this.formErrors )
        {
            if ( !this.formErrors.hasOwnProperty(field) )
            {
                continue;
            }
            // Clear previous errors
            this.formErrors[field] = {};
            // Get the control
            const control = this.formPersonalRecord.get(field);
            if ( control && control.dirty && !control.valid )
            {
                this.formErrors[field] = control.errors;
            }
        }
  }

  ngOnInit() {
    this.formPersonalRecord = this.builder.group({
      firstName:              ['', Validators.required],
      lastName:               ['', Validators.required],
      email:                  ['', Validators.required],
      fatherName:             ['', Validators.required],
      dateOfBirth:            ['', Validators.required],
      addressPermanent:       ['', Validators.required],
      addressCurrent:         ['', Validators.required],
      gender:                 ['', Validators.required],
      maritalStatus:          ['', Validators.required],
      religion:               ['', Validators.required],
      cast:                   ['', Validators.required]
    });

    this.formErrors = {
      firstName:        {},
      lastName:         {},
      email:            {},
      fatherName:       {},
      dateOfBirth:      {},
      addressPermanent: {},
      addressCurrent:   {},
      gender:           {},
      maritalStatus:    {},
      religion:         {},
      cast:             {}
    };
    this.formPersonalRecord.valueChanges.subscribe(() => {
      this.onFormValuesChanged();
    });
  }
}

formControlname 上有拼写错误。其 formControlName 为大写 N。

分叉堆栈闪电战 https://stackblitz.com/edit/angular-hcr8bl-rnayva

建议 ：

您不应该在 mat-error 上添加 *ngIf。垫子错误的全部目的是避免做这样的事情。

你应该使用 mat-form-field 组件来包装你的输入

那么你可以简单地尝试一下：

<form [formGroup]="formPersonalRecord">
    <mat-form-field class="full-width-input">
       <input matInput placeholder="First Name" formControlName="firstName" />
          <mat-error>
                Please provide name.
          </mat-error>
    </mat-form-field>
...