如何调用vue组件的函数？

export default {
  data() {
    return {
      message: 'Hello Vue!'
    }
  },
  methods: {
    showMessage() {
      console.log(this.message);
    }
  }
}

import MyComponent from './MyComponent.vue'

<template>
  <div>
    <my-component ref="myComponentRef"></my-component>
  </div>
</template>

export default {
  methods: {
    callComponentFunction() {
      this.$refs.myComponentRef.showMessage();
    }
  }
}