取消选中 Ionic 4 中的单选按钮

Uncheck radio button in Ionic 4

如何在 Ionic 4 中取消选中单选按钮或重置单选组?

这不起作用(在 Ionic 2 之前一直有效):

  <form [formGroup]="myForm">
    <ion-list formControlName="listOptions">
      <ion-radio-group>

        <ion-item class="bgtransparent" [ngClass]="{'bgred': correctAnswerFirst}">
          <ion-radio value="answer1" (ionSelect)="processSelectedAnswer(1)"></ion-radio>
          <ion-label>{{answer1}}</ion-label>
        </ion-item>

        <ion-item class="bgtransparent" [ngClass]="{'bgred': correctAnswerSecond}">
          <ion-radio value="answer2" (ionSelect)="processSelectedAnswer(2)"></ion-radio>
          <ion-label>{{answer2}}</ion-label>
        </ion-item>

        <ion-item class="bgtransparent" [ngClass]="{'bgred': correctAnswerThird}">
          <ion-radio value="answer3" (ionSelect)="processSelectedAnswer(3)"></ion-radio>
          <ion-label>{{answer3}}</ion-label>
        </ion-item>

        <ion-item class="bgtransparent" [ngClass]="{'bgred': correctAnswerFourth}">
          <ion-radio value="answer4" (ionSelect)="processSelectedAnswer(4)"></ion-radio>
          <ion-label>{{answer4}}</ion-label>
        </ion-item>
      </ion-radio-group>

    </ion-list>
  </form>

.

this.myForm = formBuilder.group({
      listOptions: ['']
    });

所以主要是这个功能不再起作用了:

this.myForm.controls.listOptions.reset();

你的 formControl 应该在 ion-radio-group 上吗?

  <form [formGroup]="myForm">
    <ion-list>
      <ion-radio-group formControlName="listOptions">