首先根據項目需求在index.html裏面佈局loading頁面，在app.vue實現圖片預加載，圖片資源加載完畢後移除loading的div
index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0">
<title>vue中實現圖片預加載及可視化百分比loading</title>
<style>
.loading{
width: 100%;
height: 100%;
background: #fef0d1;
position: fixed;
top: 0;
left: 0;
right: 0;
bottom: 0;
display: flex;
justify-content: center;
align-items: center;
flex-direction: column;
z-index: 9999999;
}
.lotxt{width: 50%;}
.outbg{
width: 5rem;
height: 1rem;
margin-top: 20px;
background: url(static/images/outb.png) no-repeat;
background-size: 100% 100%;
display: flex;
justify-content: center;
align-items: center;
}
.inbg{
width: 4rem;
height: 0.5rem;
background: url(static/images/inb.png) no-repeat;
background-size: 100% 100%;
}
.bar{
width: 4rem;
height: 0.5rem;
background: url(static/images/bar.png) no-repeat;
background-size: 0 100%;
}
</style>
</head>
<body>
<div id="Loading">
<div class="loading">
<img class="lotxt" src="static/images/loading.png" alt="">
<div class="outbg">
<div class="inbg">
<-- 進度條 -->
<div id="_bar" class="bar"></div>
</div>
</div>
</div>
</div>
<div id="app"></div>
<!-- built files will be auto injected -->
</body
</html>
app.vue
<template>
<div id="app">
<router-view/>
</div>
</template>
<script>
export default {
name: 'App',
data(){
return{
count: 0,
percent:'',
imglength:0
}
},
mounted(){
this.preload()
},
methods:{
preload: function() {
let imgs = [
"static/images/bgbottom.png",
"static/images/bgbtn.png",
"static/images/bgtop.png",
"static/images/center.png",
"static/images/hdxz.png",
"static/images/main.png",
"static/images/pan.png",
"static/images/point.png",
"static/images/pop.png",
"static/images/title.png",
"static/images/uping.png",
"static/images/xiong.png",
"static/images/xpstyle.png",
"static/images/loading.png",
"static/images/bar.png",
"static/images/inb.png",
"static/images/outb.png",
"static/images/share.jpeg",
]
this.imglength = imgs.length
for (let img of imgs) {
let image = new Image()
image.src = img
image.onload = () => {
this.count++
// 計算圖片加載的百分數，綁定到percent變量
let percentNum = Math.floor(this.count / this.imglength * 100)
this.percent = `${percentNum}%`
document.getElementById('_bar').style.backgroundSize = `${percentNum}% 100%`
// console.log(this.percent)
}
}
},
},
watch: {
count: function(val) {
if (val === this.imglength) {
document.body.removeChild(document.getElementById('Loading'))
}
}
}
}
</script>
注意：圖片需要放在static裏面