validation - 使用反应式表单中的嵌套表单组处理 Angular2 - 4 错误

Question

伙计们，我需要一些关于 Angular 4 反应形式的帮助。除了验证之外，我嵌套的表单组也可以正常工作。但是当我尝试在我的 html 标记中添加一些处理验证时，我的应用程序崩溃了。

我的组件代码如下所示：

createForm() {
    let options: any = {};

    for (let option of this.annoucementOptions) {
        options[option.title] = new FormControl(false);
    }

    let optionsFormGroup: FormGroup = new FormGroup(options);

    this.annoucementForm = this.fb.group({
        address: this.fb.group({
            country: ['', [Validators.maxLength(50)]],
            state: ['', [Validators.maxLength(50)]],
            city: ['', [Validators.required, Validators.maxLength(50)]],
            street: ['', [Validators.required, Validators.maxLength(50)]],
            apartment: ['', [Validators.required, Validators.maxLength(50)]],
        }),
        description: this.fb.group({
            title: ['', [Validators.required, Validators.maxLength(80)]],
            shortDescription: [''],
            livingPlaces: [''],
            room: [''],
            options: optionsFormGroup
        }),
        priceBlock: this.fb.group({
            price: ['', [Validators.required, Validators.maxLength(80)]],
            type: ['', [Validators.required, Validators.maxLength(80)]],
        }),
    });
}

这是我的一段模板代码：

<form class="form form-lg form-def" *ngIf="annoucementForm" (ngSubmit)="saveDetails(annoucementForm)"  name="annoucementForm" [formGroup]="annoucementForm">
<div class="form-block"  formGroupName="address">
    <h2 class="form-block-heading flag-label primary">Address</h2>

    <ul class="row form-list">
        <li class="col-md-6 col-lg-4 form-list-item">
            <md-input-container class="d-block">
                <input type="text" mdInput placeholder="*Country" formControlName="country">
            </md-input-container>

            <div  class="form-error text-danger"
                  *ngIf="annoucementForm.get('country').touched "
            >
                <p *ngIf="annoucementForm.get('country').hasError('maxlength')">
                    *This field be more than 35 characters long.
                </p>
            </div>
        </li>
   </ul>

Answer 1

利用

annoucementForm.get('address.country') 

或者

annoucementForm.get(['address', 'country'])

代替

annoucementForm.get('country')