在vue中动态添加class类进行显示隐藏实例

<div class="status_button">
       <el-button type="success" @click="checkSite" >查岗</el-button>
       <el-button type="danger">视频</el-button>
     </div>
     <!-- 查岗部分显示影藏 -->
     <div class="check_button" :class="[this.flag?'show':'hidden']">
      <ul class="cl">
       <li>用xinhic</li>
       <li>xin231</li>
      </ul>
     </div>

data() {
  return {
   flag: false,
  }
 },
 methods: {
  getdata() {
   this.$axios.post('http://yapi.xxxxxxx').then( res => {
    console.log(res)
   })
  },
  checkSite() {
   this.flag = !this.flag
  }
 }