1、获取支付二维码

<el-button
  @click="getQRcode(item)"
  type="primary"
 >扫码</el-button>
async getQRcode(item) {
  let res = await Type["payOnline"]({传递接口需要的参数})
  if(res.code!==1) return this.$message.error(res.message)
  this.appOrderNo = res.data.appOrderNo;
  window.open(res.data.url, '_blank');
  this.startTime()
},

2、倒计时，查询支付结果

startTime() {
  this.t = setInterval(() => {
    this.getQcodeVanish();
    if (this.time == 0) {
    } else {
      this.time--;
    }
  }, 2000);
},
async getQcodeVanish(){
  let res = await Type["loadPayStatus"]({
    appOrderNo:this.appOrderNo,
  })
  console.log(res, "支付结果");
  if(res.code!==1) return this.$message.error(res.message);
  if(res.data){
    this.$message.success(res.message)
    clearInterval(this.t);
    this.Save()
  }
},