最近在改写一个网站，抽离公共组件的时候，发现一个nav组件图标是用background-image显示的。把基本的框架抽离出去，具体菜单项用插槽，然后图片需要用props传参。写了一个小案例。
父组件
Home.vue

<template>
  <div class="home">
    <button @click="changeBackground">切换图片背景</button>
    <br>
    <br>
    <HelloWorld :bgPath="bgPath"></HelloWorld>
  </div>
</template>

<script>
import HelloWorld from '@/components/HelloWorld.vue';
//import引入图片获得真实的路径
import picPath from '@/views/images/seeSee.jpg';
import picPath2 from '@/views/images/lai.jpg';

export default {
  name: 'Home',
  components: {
    HelloWorld
  },
  data() {
    return {
      bgPath: picPath
    }
  },
  methods: {
    //测试切换背景图片
    changeBackground() {
      this.bgPath = picPath2;
    }
  }
}
</script>

子组件
HelloWorld.vue

<template>
  <div class="hello" :style="bgStyle"></div>
</template>

<script>
export default {
  name: 'HelloWorld',
  props: {
    bgPath: {
      type: String,
      default: ''
    },
  },
  computed: {
    //这里可以用计算属性也可以用watch
    bgStyle() {
      return {
        backgroundImage: 'url(' + this.bgPath + ')'
      }
    }
  }
}
</script>

<style scoped>
.hello {
  width: 400px;
  height: 200px;
  border: 5px solid red;
  background-repeat: no-repeat;
  background-size: cover;
}
</style>