uni-app实现获取验证码倒计时功能

<template>
 <view>
 <view class="three">
 <view class="get" @tap="getCheckNum()">
 <text>{{!codeTime?'获取验证码':codeTime+'s'}}</text>
 </view>
 <view class="all">
 <view class="left">验证码</view>
 <input v-model="mydata.checkNum" placeholder="请输入验证码"/>
 </view>
 <button class="btn" @tap='sure'>确认</button>
 </view>
 </view>
</template>

<script>
 export default {
 data() {
 return {
  codeTime:0,
 }
 },
  methods: {
   getCheckNum(){
 if(this.codeTime>0){
  uni.showToast({
  title: '不能重复获取',
  icon:"none"
  });
  return;
 }else{
  this.codeTime = 60
  let timer = setInterval(()=>{
  this.codeTime--;
  if(this.codeTime<1){
  clearInterval(timer);
  this.codeTime = 0
  }
  },1000)
    }
   }
  }
}

.all{
 margin: 30rpx;
 border-bottom: 2rpx solid #EEEEEE;
 display: flex;
 flex-wrap: nowrap;
}
.left{
 margin-bottom: 30rpx;
 margin-right: 40rpx;
 width: 150rpx;
}
.three{
 background-color: white;
 width: 92%;
 border-radius: 10rpx;
 padding: 20rpx 0;
 margin: 20rpx auto;
 position: relative;
}
.btn{
 background-color: orange;
 font-size: 28rpx;
 width: 160rpx;
 height: 70rpx;
 line-height: 70rpx;
 margin-: 40rpx;
 color: white;
 font-weight: 600;
}
.get{
 position: absolute;
 : 40rpx;
 right: 30rpx;
 background-color: orange;
 height: 70rpx;
 line-height: 70rpx;
 color: white;
 border-radius: 10rpx;
 padding: 0 20rpx;
}