秒数倒计时

使用场景

用于发送短信等耗费操作时，不要依赖前端验证，必须一定要同时在后端进行ratelimit验证。

• 短信验证重发的场景中。一般为60s, 120s

API

参数	说明	类型	默认值
time	可选，计时秒数	Number	60
start	可选，默认自动倒计时，设为false时可以手动开始计时	Boolean	true

Demo

``` vux height=65 components=Group,Cell,Countdown

export default { methods: { finish: function (index) { this.show = false this.value = 'completed' console.log('current index', index) } }, data () { return { show: true, value: '' } } }

``` vux height=125 components=Group,Cell,Countdown,Switch
<template>
<group>
  <switch title="start" :value.sync="start"></switch>
  <cell title="15s">
    <countdown slot="value" :time="time" :start="start" @on-finish="finish"></countdown>
  </cell>
</group>
</template>

<script>
export default {
  methods: {
    finish: function (index) {
      this.start = false
      this.time = 20
    }
  },
  data () {
    return {
      time: 15,
      start: false
    }
  }
}
</script>