使用 hasError() 进行验证的表单生成器会引发 ERROR TypeError 的错误:无法读取未定义的属性“hasError" [英] Form Builder with hasError() for validation throws an error of ERROR TypeError: Cannot read property 'hasError' of undefined

问题描述

我正在使用 Form Builder 实现一个 angular 2 的表单

在 component.ts 中，我使用 formGroup 实现了我的表单

下面是我的代码

public myForm: FormGroup;构造函数(私有身份验证服务:AuthenticateService，私人_fb:FormBuilder){}ngOnInit() {this.myForm = this._fb.group({地址:[this.userDetails.address，[Validators.required]]，address2: ['', [Validators.required]],城市:['', [Validators.required]],company_address: ['', [Validators.required]],company_address2: ['', [Validators.required]],company_city: ['', [Validators.required]],company_country: ['', [Validators.required]],公司: ['', [Validators.required , Validators.minLength(3)] ],company_tax_number: ['', [<any>Validators.required]],company_zip: ['', [<any>Validators.required, Validators.minLength(5), Validators.maxLength(7)]],国家:['', [Validators.required]],电子邮件:['', [Validators.required, Validators.email]],first_name: [this.userDetails.first_name, [<any>Validators.required]],id: ['', [Validators.required]],last_name: ['', [Validators.required]],电话:['', [Validators.required, Validators.minLength(10)]],zip: ['', [<any>Validators.required , Validators.minLength(5) , Validators.maxLength(7)]],user_type: ['2', [Validators.required]],条款:[0，[Validators.required]]，井号: ['']，});}

它工作正常.但是在前端显示验证时

我是这样用的

 
<div class="col-lg-8"><label>地址 2</label><textarea class="form-control" placeholder="Address" rows="2" [readonly]="disabled" id="companyaddress2" formControlName="company_address2"></textarea><span class="help-block form-error text-danger small" *ngIf="myForm.controls['company_address2'].hasError('required')">公司地址 2 是必需的.</span>

它正在工作，但在控制台中抛出错误，如下所示

错误类型错误:无法读取未定义的属性hasError"

请帮我如何排序.

谢谢.

解决方案

你应该像这样使用它:

 公司地址 2 是必需的 </span>

Hi I am implementing a form in angular 2 using Form Builder

in component.ts i have implemented my form using formGroup

Below is My code

public myForm: FormGroup;

constructor(private authenticateservice: AuthenticateService,
              private _fb: FormBuilder
             ) {


}

ngOnInit() {

this.myForm = this._fb.group({
      address: [this.userDetails.address, [<any>Validators.required]],
      address2: ['', [<any>Validators.required]],
      city: ['', [<any>Validators.required]],
      company_address: ['', [<any>Validators.required]],
      company_address2: ['', [<any>Validators.required]],
      company_city: ['', [<any>Validators.required]],
      company_country: ['', [<any>Validators.required]],
      company: ['', [<any>Validators.required , Validators.minLength(3)] ],
      company_tax_number: ['', [<any>Validators.required]],
      company_zip: ['', [<any>Validators.required,  Validators.minLength(5) , Validators.maxLength(7)]],
      country: ['', [<any>Validators.required]],
      email: ['', [<any>Validators.required, Validators.email]],
      first_name: [this.userDetails.first_name, [<any>Validators.required]],
      id: ['', [<any>Validators.required]],
      last_name: ['', [<any>Validators.required]],
      phone: ['', [<any>Validators.required, Validators.minLength(10)]],
      zip: ['', [<any>Validators.required , Validators.minLength(5) , Validators.maxLength(7)]],
      user_type: ['2', [<any>Validators.required]],
      terms: [0, [<any>Validators.required]],
      hash_tag: [''],

    });

}

It is working fine. But when coming to display validations in frontEnd

I used like this

  <div class="form-group row">
    <div class="col-lg-8">
      <label>Address 2</label>
      <textarea class="form-control" placeholder="Address" rows="2" [readonly]="disabled" id="companyaddress2" formControlName="company_address2"></textarea>
      <span class="help-block form-error text-danger small" *ngIf="myForm.controls['company_address2'].hasError('required')">Company Address 2 is Required.</span>
    </div>
  </div>

it is working but throwing the error in console like Below

ERROR TypeError: Cannot read property 'hasError' of undefined

Please Help me how to sort this.

Thank You.

解决方案

You should use it like this:

<span class="help-block form-error text-danger small" 
  *ngIf="myForm.controls['company_address2'].errors?.required &&
  myForm.controls['company_address2'].touched">Company Address 2 is Required </span>

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