在列表中动态设置元素的id

<div class="col-6" v-for="(item,i)  in showpics" :key="i">
              <img
                class="showpic"
                src="../assets/dllogo.png"
                :id="getId('showpic',i)"
              />
</div>
......
getId(idcommon, i) {
      return idcommon + i;
    }