//main.js文件中
Vue.directive("color", {
  鉤子函數(shù)
})

<template>
    <div class="combox">
        <div v-for="(item,index) in listArr" :key="index">
            人物{{ item.name }}---- 描述 {{ item.dec}}
        </div>
    </div>
</template>
<script>
    export default {
        props: {
            listArr: {
                type: Array,
                default: () => []
            },
       },
    }
</script>

<template>
    <div class="loadingcssbox">
      <img src="../../assets/loading.gif"/>
    </div>
</template>

import Vue from 'vue'
//引入加載動(dòng)畫組件
import LoadingCom from './LoadingCom.vue'
const loadingDirectiive = {
    inserted(el, bing) { 
      // el ==>表示被綁定了指令的那個(gè)元素，這個(gè)el是一個(gè)原生的js對(duì)象。
      // bing ==> 指令相關(guān)的信息
      // 得到一個(gè)組件的構(gòu)造函數(shù)
      const loadingCtor = Vue.extend(LoadingCom)
      // 得到實(shí)例loadingComp
      const loadingComp = new loadingCtor()
      // 獲取實(shí)例的html
      const htmlLoading = loadingComp.$mount().$el
      // 將html放在el的實(shí)例上面去
      el.myHtml = htmlLoading
      if (bing.value) { 
          appendHtml(el)
      }
    },
    update(el, bing) { 
      // bing.value 是v-loading綁定的那個(gè)值； true 要顯示加載動(dòng)畫
      //新值 bing.value與舊值bing.oldValue是否相等
      if (bing.value !== bing.oldValue ) { 
          bing.value ? appendHtml(el) : removeHtml(el)
      }
    }
}
function appendHtml(el) { 
  el.appendChild(el.myHtml)
}
function removeHtml(el) { 
  el.removeChild(el.myHtml)
}
export default loadingDirectiive

// 得到一個(gè)組件的構(gòu)造函數(shù)
const loadingCtor = Vue.extend(LoadingCom)
// 得到實(shí)例loadingComp
const loadingComp = new loadingCtor()
// 獲取實(shí)例的html。將html放在el的實(shí)例上面去。
// 放在el實(shí)例上的優(yōu)勢(shì)是方便訪問(wèn)。
// $el是可以訪問(wèn)加載動(dòng)畫的html。
// 這樣就可以將它添加到某一個(gè)節(jié)點(diǎn)上。同時(shí)也方便移除
const htmlLoading = loadingComp.$mount().$el
el.myHtml = htmlLoading 

import loadingDirectiive from './components/loading/loading'
Vue.directive('loading', loadingDirectiive)
<!-- 全局指令的注冊(cè)方式 -->
Vue.directive("color", {
  鉤子函數(shù)
})

<template>
  <div class="box">
    <ListCom :listArr="listArr" v-loading="isLoadFlag"></ListCom>
  </div>
</template>
<script>
import ListCom from '../components/ListCom.vue'
export default {
  components: {
    ListCom
  },
  data() {
    return {
      listArr: [],
      //通過(guò)isLoadFlag來(lái)控制動(dòng)畫是否開(kāi)啟
      isLoadFlag:false,
    }
  },
  created() { 
    this.sendAPi()
  },
  methods: {
    sendAPi() { 
      this.isLoadFlag = true;//開(kāi)啟加載動(dòng)畫
      setTimeout(() => { 
        this.listArr = [
          { name: '齊玄幀', dec: '五百年前的呂祖', },
          { name: '王仙芝', dec: '白帝轉(zhuǎn)世' },
          { name: '李淳罡', dec: '李淳罡當(dāng)初的實(shí)力是絕對(duì)的天下第一的' },
          { name: '鄧太阿', dec: '徐鳳年的舅舅' },
          { name: '曹長(zhǎng)卿', dec: '這位號(hào)稱獨(dú)占天象八斗風(fēng)流，實(shí)力排進(jìn)天下前三' }
        ]
        //移除加載動(dòng)畫
        this.isLoadFlag = false
      },3000)
    }
  }
}
</script>

<template>
    <div class="showimgbox">
        <img src="../../assets/nodata.png"/>
        <p>暫無(wú)數(shù)據(jù)</p>
    </div>
</template>

import Vue from 'vue'
import ShowImgCom from './ShowImgCom.vue'
const showimgDirectiive = {
  inserted(el, bing) {
    const showimgCtor = Vue.extend(ShowImgCom)
    const showImgComp = new showimgCtor()
    const htmlSHowPic = showImgComp.$mount().$el
    el.myHtml = htmlSHowPic
    if (bing.value) {
        appendHtml(el)
    }
  },
  update(el, bing) {
    if (bing.value !== bing.oldValue) {
      bing.value ? appendHtml(el) : removeHtml(el)
    }
  }
}
function appendHtml(el) {
  el.appendChild(el.myHtml)
}
function removeHtml(el) {
  el.removeChild(el.myHtml)
}
export default showimgDirectiive

import showimgDirectiive from './components/ShowImg/showimg'
Vue.directive('showimg', showimgDirectiive)

<template>
  <div class="box" v-showimg="showImgFlag">
    <ListCom :listArr="listArr" v-loading="isLoadFlag"></ListCom>
  </div>
</template>
<script>
import ListCom from '../components/ListCom.vue'
export default {
  components: {
    ListCom
  },
  data() {
    return {
      listArr: [],
      isLoadFlag: false,
      showImgFlag:false
    }
  },
  created() { 
    this.sendAPi()
  },
  methods: {
    sendAPi() { 
      this.isLoadFlag = true;//加載中
      setTimeout(() => { 
        this.listArr = []
        this.isLoadFlag = false 
        //是否顯示占位圖
        if (this.listArr && this.listArr.length === 0) {
          this.showImgFlag = true
        } else { 
          this.showImgFlag =false
        }
      },3000)
    }
  }
}
</script>