//
<template>
  <section v-show="bool">11</section>
</template>
<script>
export default {
  data() {
    return {
      bool: false
    };
  },
  mounted() {
  },
  methods: {
    aaa() {
      let that = this;
      that.bool = true;
      console.log(that.bool);
      setTimeout(() => {
        that.bool = false;
        console.log(that.bool);
      }, 2000);
    }
  }
};
</script>
< hr >
//
<template>
  <section>
      <zujian></zujian>
  </section>
</template>
<script>
import zujian from "@/components/zujian";
export default {
  data() {
  },
  mounted() {
    zujian.methods.aaa();
  },
  components: {
    zujian
  }
};
</script>
 after the parent component is called, the  console  of the child component is correct twice, but the state of the child component does not change. 

