vue实现验证码倒计时按钮

<div v-bind:class="{ 'text_email': isActive, 'text_tip': isTip }">{{tip}}</div> //出错提示<div class="input">    <i class="ret_icon-email"></i>    <input       type="text"       v-model="email"       v-bind:class="{ 'input_email0' : hasError }"       v-on:click="cancelError"       :placeholder="输入邮箱地址"       id="inputEmail"    />    <br />    <input type="text" placeholder="输入验证码" class="input_number" />    <button class="btn_number" v-bind:class="{gray:wait_timer>0}" @click="getCode()">        <span           class="num_green"           v-show="showNum"           v-bind:class="{num:wait_timer>0}"        >{{this.wait_timer + "s "}}</span>        <span           class="span_number"           v-bind:class="{gray_span:wait_timer>0}"        >{{ getCodeText() }}</span>    </button>    <br /></div>

data() {    return {      tip: "用Email找回密码",      isTip: false,      isActive: true,      showNum: false,      wait_timer: false,      hasError: false,      email: ""    }},methods: {    cancelError: function(event) {      this.hasError = false;      this.isActive = true;      this.isTip = false;      this.tip = "用Email找回密码";    },    getCode: function() {      if (this.wait_timer > 0) {        return false;      }      if (!this.email) {        this.hasError = true;        this.isActive = false;        this.isTip = true;        this.tip = "Email不能为空";        return false;      }      if (        !/^([a-zA-Z0-9]+[_|/_|/.]?)*[a-zA-Z0-9]+@([a-zA-Z0-9]+[_|/_|/.]?)*[a-zA-Z0-9]+/.[a-zA-Z]{2,3}$/.test(          this.email        )      ) {        this.hasError = true;        this.isActive = false;        this.isTip = true;        this.tip = "Email地址无效";        return false;      }      this.showNum = true;      this.wait_timer = 120;      var that = this;      var timer_interval = setInterval(function() {        if (that.wait_timer > 0) {          that.wait_timer--;        } else {          clearInterval(timer_interval);        }      }, 1000);      //在这里调取你获取验证码的ajax    },    getCodeText: function() {      if (this.wait_timer > 0) {        return "已发送";      }      if (this.wait_timer === 0) {        this.showNum = false;        return "重新发送验证码！";      }      if (this.wait_timer === false) {        return "发送验证码！";      }    },}

.ret_icon-email {  background: url(../../assets/pics/email.svg) no-repeat; //图片为本地图片  width: 20px;  height: 20px;  position: absolute;  top: 12px;  left: 16px;}.input_email0 {  border: 1px solid rgba(239, 83, 80, 1);}.input_number {  width: 112px;  height: 44px;  text-indent: 16px;  margin-right: 12px;}.btn_number {  width: 154px;  height: 44px;  border-radius: 4px;  box-sizing: border-box;  border: 1px solid rgba(76, 175, 80, 1);  line-height: 16px;  outline: none;}.span_number {  color: rgba(76, 175, 80, 1);}.btn_number.gray {  background: rgba(242, 244, 245, 1);  border: 1px solid rgba(0, 0, 0, 0.05);}.span_number.gray_span {  color: #9a9c9a;}.num_green.num {  color: rgba(76, 175, 80, 1);}