利用vuejs实现带有进度条的延迟加载

如何利用vuejs实现带有进度条的延迟加载，下面编程教程网小编给大家详细介绍一下实现代码！

安装脚手架

npm i lodash.random

实现代码：

<template>
  <p :class="{'loading-container': true, loading: isLoading, visible: isVisible}">
    <p class="loader" :style="{ width: progress + '%' }">
      <p class="light"></p>
    </p>
    <p class="glow"></p>
  </p>
</template>
<script>
import random from 'lodash.random'
import $eventHub from '../components/eventHub'
// 假设加载将在此时间内完成。
const defaultDuration = 8000 
// 更新频率
const defaultInterval = 1000 
// 取值范围 0 - 1. 每个时间间隔进度增长多少
const variation = 0.5 
// 0 - 100. 进度条应该从多少开始。
const startingPoint = 0 
// 限制进度条到达加载完成之前的距离
const endingPoint = 90
export default { 
  data: () => ({
    isLoading: true, // 加载完成后，开始逐渐消失
    isVisible: false, // 完成动画后，设置 display: none
    progress: startingPoint,
    timeoutId: undefined,
  }),

  mounted() {
    $eventHub.$on('asyncComponentLoading', this.start)
    $eventHub.$on('asyncComponentLoaded', this.stop)
  },
 
  methods: {
    start() {
      this.isLoading = true
      this.isVisible = true
      this.progress = startingPoint
      this.loop()
    },

    loop() {
      if (this.timeoutId) {
        clearTimeout(this.timeoutId)
      }
      if (this.progress >= endingPoint) {
        return
      }
      const size = (endingPoint - startingPoint) / (defaultDuration / defaultInterval)
      const p = Math.round(this.progress + random(size * (1 - variation), size * (1 + variation)))
      this.progress = Math.min(p, endingPoint)
      this.timeoutId = setTimeout(
        this.loop,
        random(defaultInterval * (1 - variation), defaultInterval * (1 + variation))
      )
    },

    stop() {
      this.isLoading = false
      this.progress = 100
      clearTimeout(this.timeoutId)
      const self = this
      setTimeout(() => {
        if (!self.isLoading) {
          self.isVisible = false
        }
      }, 200)
    },
  },
}
</script>
<style scoped>
.loading-container {
  font-size: 0;
  position: fixed;
  top: 0;
  left: 0;
  height: 5px;
  width: 100%;
  opacity: 0;
  display: none;
  z-index: 100;
  transition: opacity 200;

}

.loading-container.visible {
  display: block;

}

.loading-container.loading {
  opacity: 1;

}

.loader {
  background: #23d6d6;
  display: inline-block;
  height: 100%;
  width: 50%;
  overflow: hidden;
  border-radius: 0 0 5px 0;
  transition: 200 width ease-out;

}

.loader > .light {
  float: right;
  height: 100%;
  width: 20%;
  background-image: linear-gradient(to right, #23d6d6, #29ffff, #23d6d6);
  animation: loading-animation 2s ease-in infinite;

}

.glow {
  display: inline-block;
  height: 100%;
  width: 30px;
  margin-left: -30px;
  border-radius: 0 0 5px 0;
  box-shadow: 0 0 10px #23d6d6;

}

@keyframes loading-animation {
  0% {
    margin-right: 100%;
  }
  50% {
    margin-right: 100%;
  }
  100% {
    margin-right: -10%;
  }

}

</style>

在App.vue中引入上面组建

在页面加载之前引入以下代码

import $eventHub from '../components/eventHub

router.beforeEach((to, from, next) => {
  if (typeof to.matched[0]?.components.default === 'function') {
    $eventHub.$emit('asyncComponentLoading', to) // 启动进度条
  }
  next()
}

router.beforeResolve((to, from, next) => {
  $eventHub.$emit('asyncComponentLoaded') // 停止进度条
  next()
})

创建eventHub.js

import Vue from 'vue'
export default new Vue()