详解vue中父子参数传递双向的方式不同

<!-- 子组件 -->
<template>
  <button @click="sendMessage">Send Message</button>
</template>

<script>
export default {
  methods: {
    sendMessage() {
      this.$emit('messageSent', 'Hello from child!');
    }
  }
};
</script>

<!-- 父组件 -->
<template>
  <div>
    <ChildComponent @messageSent="handleMessage" />
  </div>
</template>

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

export default {
  components: {
    ChildComponent
  },
  methods: {
    handleMessage(message) {
      console.log(message); // 'Hello from child!'
    }
  }
};
</script>

<!-- 父组件 -->
<template>
  <div>
    <ChildComponent :message="parentMessage" />
  </div>
</template>

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

export default {
  components: {
    ChildComponent
  },
  data() {
    return {
      parentMessage: 'Hello from parent!'
    };
  }
};
</script>

<!-- 子组件 -->
<template>
  <div>
    {{ message }}
  </div>
</template>

<script>
export default {
  props: ['message']
};
</script>