如何在Vue中更改子组件数据？

<template>
  <div>
    <child-component :message="message" @update-message="updateMessage"></child-component>
  </div>
</template>

<script>
import ChildComponent from './ChildComponent.vue';

export default {
  components: {
    ChildComponent
  },
  data() {
    return {
      message: 'Hello Vue!'
    };
  },
  methods: {
    updateMessage(newMessage) {
      this.message = newMessage;
    }
  }
};
</script>

<template>
  <div>
    <button @click="changeMessage">Change Message</button>
    <p>{{ message }}</p>
  </div>
</template>

<script>
export default {
  props: ['message'],
  methods: {
    changeMessage() {
      const newMessage = 'Updated Message';
      this.$emit('update-message', newMessage);
    }
  }
};
</script>

<template>
  <div>
    <child-component ref="childComponent"></child-component>
    <button @click="changeMessage">Change Message</button>
  </div>
</template>

<script>
import ChildComponent from './ChildComponent.vue';

export default {
  components: {
    ChildComponent
  },
  methods: {
    changeMessage() {
      const newMessage = 'Updated Message';
      this.$refs.childComponent.message = newMessage;
    }
  }
};
</script>

<template>
  <div>
    <p>{{ message }}</p>
  </div>
</template>

<script>
export default {
  data() {
    return {
      message: 'Hello Vue!'
    };
  }
};
</script>