属性 'controls' 在类型 'AbstractControl' 上不存在 Angular 4

Property 'controls' does not exist on type 'AbstractControl' Angular 4

我正在尝试 Angular 4 中的嵌套反应形式。它工作正常但是当我尝试构建 AOT 时它抛出错误

'controls' does not exist on type 'AbstractControl'

我用谷歌搜索并尝试了一些东西,但没有成功。谁能告诉我如何解决这个问题?

<div [formGroup]="myForm">
    <div formArrayName="addresses">
        <div *ngFor="let address of myForm.get('addresses').controls; let i=index" 
                    class="panel panel-default">
            <span *ngIf="myForm.get('addresses').length > 1"
                    (click)="removeAddress(i)">Remove</span>
            <div [formGroupName]="i">
                <mat-form-field>
                    <input matInput formControlName="city" placeholder="city" value="">
                </mat-form-field>
            </div>

        </div>
    </div>
    <a (click)="addAddress()" style="cursor: default"> Add +</a>
</div>

下面的打字稿代码

constructor(private _fb: FormBuilder) {     
}

ngOnInit() {
    this.myForm = this._fb.group({
        addresses: this._fb.array([
            this.initAddress(),
        ])
    });
}
initAddress() {
    return this._fb.group({
        city: ['']
    });
}
addAddress() {
    const control = <FormArray>this.myForm.get('addresses');
    control.push(this.initAddress());
}
removeAddress(i: number) {
    const control = <FormArray>this.myForm.get('addresses');
    control.removeAt(i);
}

要获得 FormArray 的长度,只需使用 length :

<span *ngIf="myForm.controls['addresses'].length > 1" (click)="removeAddress(i)">Remove</span>

希望对您有所帮助

根据@Günter Zöchbauer 的评论,首先我更改了

myForm.controls['addresses']myForm.get('addresses') html 和 typescript

然后根据@yuruzi 评论

已将 myForm.get('addresses').controls 更改为 myForm.get('addresses')['controls']

它现在工作正常。谢谢@gunter & yuruzi

myForm.get('addresses').controls 更改为 myForm.get('addresses').value 也会解决此问题。

不过您可以轻松修复它。将 "get the controls" 逻辑外包到组件代码(.ts 文件)的方法中:

getControls() {
  return (this.recipeForm.get('controlName') as FormArray).controls;
}

在模板中,您可以使用:

*ngFor="let ingredientCtrl of getControls(); let i = index"

由于 TS 的工作方式和 Angular 解析您的模板(它不理解那里的 TS),因此需要进行此调整。

对于验证错误使用...

<span *ngIf="f.YOUR_FORM_KEY.controls.YOUR_FORM_KEY.errors?.YOUR_FORM_VALIDATION">YOUR_FORM_KEY is YOUR_FORM_VALIDATION</span>

例如

<span *ngIf="f.name.controls.name.errors?.required">Name is required</span>

ts 文件

get f(): any {
    return this.userForm.controls;
}

作为对@sunny kashyap 解决方案的更新,我会这样写:

getControls() {
  return (this.recipeForm.get('controlName') as FormArray).controls;
}

可以使用自定义界面

// Define AbstractFormGroup
export interface AbstractFormGroup extends FormGroup {
  controls: {
    [key: string]: AbstractFormGroup & AbstractFormGroup[] & AbstractControl & FormGroup & FormArray,
  }
}

// Usage example
class ... {
  myForm: AbstractFormGroup
  ...
  this.myForm = this.fb.group({...}) as AbstractFormGroup
}