类型 'AbstractControl' 上不存在 Angular 5 嵌套窗体和验证以及属性'controls'

Question

我已经设置了一个嵌套的FormGroup。到目前为止，一切都很好。但是我不确定在有嵌套表单元素时如何正确设置验证警报。

发生的一件特殊的事情是在构建过程中我会出错：属性"控件"不存在于类型的" AbstractControl"

这是我的代码：

import { Component, OnInit } from '@angular/core';
import { Validators, FormControl, FormGroup, FormBuilder } from '@angular/forms';
@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent implements OnInit {
  name = 'Reactive Form - Nested FormGroups';
  myForm: FormGroup;
  constructor(
    private fb: FormBuilder
  ) {}
  ngOnInit() {
    this.buildForm();
  }
  buildForm() {
    this.myForm = this.fb.group({
      user : this.fb.group({
        'firstName': new FormControl('', Validators.required),
        'lastName': new FormControl('', Validators.required)
      }),
      'bio': new FormControl()
    });
  }
}

我的问题是在验证中请参见class ="验证 - 消息"

的div

<hello name="{{ name }}"></hello>
<form [formGroup]="myForm">
  <div class="my-box" formGroupName="user">
    <label>
      First Name
      <input type="text" formControlName="firstName">
      <div class="validation-message" *ngIf="!myForm.controls.user.controls['firstName'].valid && myForm.controls.user.controls['firstName'].dirty">
        This field is invalid
      </div>
    </label>
  </div>
  <div class="my-box" formGroupName="user">
    <label>
      Last Name
      <input type="text" formControlName="lastName">
    </label>
  </div>
  <div class="my-box">
    <label for="bio" class="block-me">Bio</label>
    <textarea formControlName="bio"></textarea>
  </div>
</form>
<p>
  Data from form: {{ myForm.value | json }}
</p>

Answer 1

您在打字稿中有错字：

 user : this.fb.group({
    'firstname': new FormControl('', Validators.required),
    'lastName': new FormControl('', Validators.required)
  })

field firstname都是小写，但在html中是骆驼：

<input type="text" formControlName="firstName">

字段名称是案例敏感的。

在您的情况下，您的打字稿应该是这样：

 user : this.fb.group({
    'firstName': new FormControl('', Validators.required),
    'lastName': new FormControl('', Validators.required)
  })

更新：

要访问HTML中的user表格组，您可以通过在打字稿中创建公共属性来完成：

  public get userGroup(): FormGroup {
    return this.myForm.get('user') as FormGroup;
  }

现在您可以在HTML中以以下方式使用：

<div class="validation-message" *ngIf="!userGroup.controls['firstName'].valid && userGroup.controls['firstName'].dirty">
          This field is invalid
</div>

Answer 2

修复错误的"属性'控件"的解决方案在类型'AbstractControl'中不存在，而是将打字稿文件中的嵌套表单项目分为其自己的控件。代码如下：

import { Component, OnInit } from '@angular/core';
import { Validators, FormControl, FormGroup, FormBuilder } from '@angular/forms';
@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent implements OnInit {
  name = 'Reactive Form - Nested FormGroups';
  myForm: FormGroup;
  userControl: FormGroup;
  constructor(
    private fb: FormBuilder
  ) {}
  ngOnInit() {
    this.buildForm();
  }
  buildForm() {
    this.userControl = this.fb.group({
      'firstName': new FormControl('', Validators.required),
      'lastName': new FormControl('', Validators.required)
    })
    this.myForm = this.fb.group({
      user : this.userControl,
      'bio': new FormControl()
    });
  }
}

html文件...

<hello name="{{ name }}"></hello>
<form [formGroup]="myForm">
  <div class="my-box" formGroupName="user">
    <label>
      First Name
      <input type="text" formControlName="firstName">
      <div class="validation-message" *ngIf="!userControl.controls['firstName'].valid && userControl.controls['firstName'].dirty">
        This field is invalid
      </div>
    </label>
  </div>
  <div class="my-box" formGroupName="user">
    <label>
      Last Name
      <input type="text" formControlName="lastName">
      <div class="validation-message" *ngIf="!userControl.controls['lastName'].valid && userControl.controls['lastName'].dirty">
        This field is invalid
      </div>
    </label>
  </div>
  <div class="my-box">
    <label for="bio" class="block-me">Bio</label>
    <textarea formControlName="bio"></textarea>
  </div>
</form>
<p>
  Data from form: {{ myForm.value | json }}
</p>

这是一个有效的示例：https：//stackblitz.com/edit/angular-nestedform