there are two child components, Nav and Down, in the parent component. I want to click on the control Down of Nav to hide, but there is no response or report any error after clicking. Why?
<div id="right">
    <Nav @click="ddshow"></Nav>
</div>
<div id="down">
    <Down v-if="dd"></Down>
</div>
<script>
export default {
  data () {
    return {
      dd: true
    }
  },
  methods: {
   ddshow: function () {
      this.dd = !this.dd
   }
  }
}
</script>
