基于vue实现图片验证码倒计时60s功能

   <div class="formitem pr">
       <img src="../../image/icon2.png" alt="">
       <input type="text" placeholder="请输入验证码">
       <img :src="identifyingcode" alt="图文验证码" class="identifyingcode" @click="updateidentifyingcode(true)">
     </div>

 <div class="formitem">
      <img src="../../image/icon2.png" alt="">
      <input type="text" placeholder="请输入验证码">
      <button class="button" type="button" name="button" @click="sendcode()" v-show="show">获取验证码</button>
      <button class="button codebtn" type="button" name="button" v-show="!show">{{sum}}s</button>
   </div>