vue里定时器setInterval的使用，短信验证码的demo

<template>
  <el-card class="box-card">
    <div slot="header" class="clearfix">
      <span>用户登录</span>
    </div>
    <el-form>
      <el-form-item>
        <el-input v-model="phoneNumber" placeholder="请输入手机号">
          <el-button slot="append" @click="getVerifyCode" :disabled="disabled">{{btnTitle}}</el-button>
        </el-input>
      </el-form-item>
      <el-form-item>
        <el-input v-model="verifyCode" placeholder="请输入验证码"></el-input>
      </el-form-item>
      <el-button type="primary" @click="onSubmit">登录</el-button>
    </el-form>
  </el-card>
</template>

<script>
export default {
  name: "",
  data() {
    return {
      phoneNumber: "",
      verifyCode: "",
      disabled: false,
      btnTitle: "获取验证码",
      temp:""
    };
  },
  methods: {
    onSubmit() {
      if(this.verifyCode==this.temp){
        console.log("登录成功,本次验证码是："+this.temp);
      }else{
        console.log("登录失败")
      }
    },
    getVerifyCode() {
      let time = 30;
      let timer = setInterval(() => {
        this.btnTitle = time + "秒后重试";
        this.disabled = true;
        time--;
        if (time == 0) {
          clearInterval(timer);
          this.btnTitle = "获取验证码";
          this.disabled = false;
        }
      }, 1000);   
      this.temp=Math.floor(Math.random()*100000)+100000;
      let regUrl =
        this.JUHE_API +
        `/json?key=m4riqdf3&secret=kLbF9WFT&from=pingda&to=86${this.phoneNumber}&text=【济源晨报】本次验证码是：${this.temp}，请不要告诉他人哦！`;
      this.$Axios.get(regUrl).then(res => {
        console.log(res);
      });
    }
  }
};
</script>

<style lang="scss" scoped>
.el-input-group__append {
  .el-button {
    padding: 4px;
  }  
}
.el-button.is-disabled, .el-button.is-disabled:focus, .el-button.is-disabled:hover{
  background: none;
}
</style>

使用elementui制作的登录框card，定义一个随机六位数数字验证码
通过短信api给输入的手机号，发送随机验证码，保存这个随机数
验证码输入后，输入框的值和保存的随机数做比较，相等即表示验证码正确

由于vue是单页面应用，
某个页面内使用定时器时，需要把定时器定义在data全局，timer:null
当需要使用时给this.timer赋值
另外，在页面组件生命周期里，需要离开页面时把定时器清理掉
regetverifyCode() {
        if(this.timer){
            clearInterval(this.timer);
            this.verifyCodeText = "获取验证码";
        }
        let time = 59;
        this.timer = setInterval(() => {
        this.verifyCodeText = `获取验证码(${time}s)`;
        this.isCanRegetverifyCodeFlag = true;
        time--;
        if (time == 0) {
        clearInterval(this.timer);
        this.verifyCodeText = "获取验证码";
        this.isCanRegetverifyCodeFlag = false;
        }
    }, 1000);
},

//另外，在页面组件生命周期里，需要离开页面时把定时器清理掉
beforeDestroy() {
    if(this.timer) {
        clearInterval(this.timer);
    }
}