要实现的效果：
点击时选中当前item，并将其他item恢复，默认选中第一个

数据处理

 data() {
       return {
           dialog:true,
           choose_grade:1,
           gradeList: [
            { label: "一年级", g_id: 1 ,choose:true  },
            { label: "二年级", g_id: 2 ,choose:false },
            { label: "三年级", g_id: 3 ,choose:false },
            { label: "四年级", g_id: 4 ,choose:false },
            { label: "五年级", g_id: 5 ,choose:false },
            { label: "六年级", g_id: 6 ,choose:false },
           ],
       }
   },

v-for循环视图列表和样式

 <div class="list">
              <div v-for="(item,index) in gradeList" :key="index">
                  <div class="grade_item" :class="item.choose ? 'grade_item_yellow':''" @click="select_grade(item.g_id)" ref="grade_item">
                      <p class="text_grade">{{item.label}}</p>
                  </div>
              </div>
            </div>

样式

 .list{
     width: 100%;
     height: 100%;
     display: flex;
     flex-direction: row; 
     // 自动换行
     flex-wrap: wrap;
     align-items: center;
     margin-top: 0.48rem;
     justify-content: center;
     
 }


.grade_item{
     width: 2.933333rem;
     height: 1.066667rem;
     background:rgba(244,244,244,1);
    //  background:rgba(255,220,32,1);
     border-radius: 0.533333rem;
     display: flex;
     margin-right: 0.4rem;
     margin-left: 0.4rem;
     flex-direction: column;
     align-items: center;
     justify-content: center;
 }
 .grade_item_yellow{
     background:rgba(255,220,32,1);
 }
 .text_grade{
    width:1.28rem;
    height:0.613333rem;
    font-size:0.426667rem;
    font-family:PingFangSC-Medium,PingFangSC;
    font-weight:bold;
    // color:rgba(102,102,102,1);
    color:#666666;
    // line-height:0.613333rem;
 }

PS图层蒙版，全屏遮罩层样式

 .popContainer{
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      z-index:22222225;
      width: 100%;
      height: 100vh;
      background: rgba(216,216,216,1);
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
  }