小编Son*_*nam的帖子

我有一个带有答案选项的问题列表，作为单选按钮字段。我从JSON文件中获得了这些问题和答案，因此正在HTML上对其进行迭代并将其值动态分配给formControlName。我的问题是在迭代控制值时如何进行验证？

*ngIf="cricketForm.control.get('ques{{i}}').invalid" 

*ngIf="cricketForm.control.get('ques{{i}}').invalid" 

这给我一个错误。如何以正确的方式来做？

https://stackblitz.com/edit/angular-yq4lyz-zt9b3h?file=app/form-field-overview-example.html 现在验证无法正常工作

html文件：

<form [formGroup]="cricketForm">
  <div *ngFor = "let user of userJson; let i =index ">
    <div class="label1" for="NameId">{{user.question}}</div>
    <mat-radio-group formControlName="ques{{i+1}}" aria-label="Select an option">
      <div *ngFor = "let option of user.options; let j =index">
        <mat-radio-button  [value]=j>{{option}}</mat-radio-button>
      </div>
    </mat-radio-group>


  <div class="invalid-feedback" *ngIf="cricketForm.control.get('ques{{i}}').invalid" >This field is required</div>
  </div>
    <button (click)="onSubmit()">Submit</button>
    <button (click)="onReset()">Reset</button>
</form>

ts文件：

ngOnInit() {
    this.cricketForm = this.formBuilder.group({
      ques1: [null, [Validators.required]],
      ques2: [null, [Validators.required]],
      ques3: [null, [Validators.required]],
      ques4: [null, [Validators.required]]
    })
    this.userDataService.getJSON().subscribe(data => {
      console.log(data);
      this.userJson = …