async/await实现图片的串行、并行加载

<!DOCTYPE html>
<html lang="en">

<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>es6</title>
<style>
img {
100%;
}
</style>
</head>

<body>
<script>
// Promise加载图片
var loadImg = (url) => {
return new Promise((resolve, reject) => {
// 创建图片
var img = new Image()
// 加载成功
img.onload = () => {
resolve(img)
}
// 图片加载
img.onerror = () => {
reject(new Error('图片加载失败'))
}
img.src = url
})
}
var imgs = ['http://img4.duitang.com/uploads/item/201411/09/20141109142633_ncKBY.thumb.700_0.jpeg',
'https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1538658203&di=2405d72f77c748c885064770074fed77&imgtype=jpg&er=1&src=http%3A%2F%2Fp1.gexing.com%2Ftouxiang%2F20120801%2F0038%2F50180a1634e49_200x200_3.jpg%3Frecache%3D20131108',
'http://img3.imgtn.bdimg.com/it/u=2423321859,2979330058&fm=27&gp=0.jpg'
]
// 并行加载
var loadImgAsync = (imgs)=>{
imgs.forEach(async (item)=>{
let img = await loadImg(item)
document.body.appendChild(img)
})
}
loadImgAsync(imgs)

// 串行加载
var ImgAsync = async (imgs) => {
for (var i = 0; i < imgs.length; i++) {
let img = await loadImg(imgs[i])
document.body.appendChild(img)
}
}
ImgAsync(imgs)
</script>
</body>

</html>
原文地址:https://www.cnblogs.com/2oex/p/9718596.html