如何在无线电组更改之前获取无线电值?

How to get the radio value before radio-group change?

我想在更改无线电值 2->0 时提醒一些事情;

当我更改无线电值 1->2 时提醒另一件事;

<ng-container *ngFor="let item of Category_D_name">
    <ion-card text-wrap>
      <ion-list radio-group [(ngModel)]="items.option" >
        <ion-list-header>
          {{ categoryOption }}.{{ item.name.SortOrder }}
        </ion-list-header>
        <ion-item>
          <ion-label>不适用</ion-label>
          <ion-radio value="0"></ion-radio>
        </ion-item>
        <ion-item>
          <ion-label>合格</ion-label>
          <ion-radio checked="true" value="1"></ion-radio>
        </ion-item>
        <ion-item>
          <ion-label>
            不合格
          </ion-label>
          <ion-radio value="2"></ion-radio>
        </ion-item>
      </ion-list>
    </ion-card>
  </ng-container>

ionChange() evnet Just give me the changed value,But I want to get the value before the change at the same time.

我认为你需要在 Temp variableionChange

的帮助下处理这个问题
 <ion-list radio-group [(ngModel)]="items.option" (ionChange)="selectedRadio($event)">

Component.ts

  tempOption: any;

  selectedRadio(event) {
     if(this.tempOption) {
        if(this.tempOption == 2 &&  event == 0) {
            // do somethig
        }  else if(this.tempOption == 1 &&  event == 2) {
            // do somethig
        }
     }
     this.tempOption = event;
    }

希望这对您有所帮助...:)