一 在main.js中引入 flexible.js
vue项目中
import './assets/js/flexible' //vue
jquery项目中
<script src="./js/flexible.js"></script>
二 flexible.js全部代码如下
(function (win, lib) {
var doc = win.document
var docEl = doc.documentElement
var metaEl = doc.querySelector('meta[name="viewport"]')
var flexibleEl = doc.querySelector('meta[name="flexible"]')
var dpr = 0
var scale = 0
var tid
var flexible = lib.flexible || (lib.flexible = {})
if (metaEl) {
console.warn('将根据已有的meta标签来设置缩放比例')
var match = metaEl.getAttribute('content').match(/initial-scale=([d.]+)/)
if (match) {
scale = parseFloat(match[1])
dpr = parseInt(1 / scale)
}
} else if (flexibleEl) {
var content = flexibleEl.getAttribute('content')
if (content) {
var initialDpr = content.match(/initial-dpr=([d.]+)/)
var maximumDpr = content.match(/maximum-dpr=([d.]+)/)
if (initialDpr) {
dpr = parseFloat(initialDpr[1])
scale = parseFloat((1 / dpr).toFixed(2))
}
if (maximumDpr) {
dpr = parseFloat(maximumDpr[1])
scale = parseFloat((1 / dpr).toFixed(2))
}
}
}
if (!dpr && !scale) {
var isAndroid = win.navigator.appVersion.match(/android/gi)
var isIPhone = win.navigator.appVersion.match(/iphone/gi)
var devicePixelRatio = win.devicePixelRatio
if(isIPhone){
if (devicePixelRatio >= 3 && (!dpr || dpr >= 3)) {
dpr = 3
} else if (devicePixelRatio >= 2 && (!dpr || dpr >= 2)) {
dpr = 2
} else {
dpr = 1
}
} else {
dpr = 1
}
scale = 1 / dpr
}
docEl.setAttribute('data-dpr', dpr)
if (!metaEl) {
metaEl = doc.createElement('meta')
metaEl.setAttribute('name', 'viewport')
metaEl.setAttribute('content', 'initial-scale=' + scale + ', maximum-scale=' + scale + ', minimum-scale=' + scale + ', user-scalable=no')
if (docEl.firstElementChild) {
docEl.firstElementChild.appendChild(metaEl)
} else {
var wrap = doc.createElement('div')
wrap.appendChild(metaEl)
doc.write(wrap.innerHTML)
}
}
function refreshRem () {
var width = docEl.getBoundingClientRect().width
if (width / dpr > 1024) {
width = 1024 * dpr
}
var rem = width / 3.75
docEl.style.fontSize = rem + 'px'
flexible.rem = win.rem = rem
}
win.addEventListener('resize', function () {
clearTimeout(tid)
tid = setTimeout(refreshRem, 300)
}, false)
win.addEventListener('pageshow', function (e) {
if (e.persisted) {
clearTimeout(tid)
tid = setTimeout(refreshRem, 300)
}
}, false)
if (doc.readyState === 'complete') {
doc.body.style.fontSize = 12 * dpr + 'px'
} else {
doc.addEventListener('DOMContentLoaded', function (e) {
doc.body.style.fontSize = 12 * dpr + 'px'
}, false)
}
refreshRem()
flexible.dpr = win.dpr = dpr
flexible.refreshRem = refreshRem
flexible.rem2px = function (d) {
var val = parseFloat(d) * this.rem
if (typeof d === 'string' && d.match(/rem$/)) {
val += 'px'
}
return val
}
flexible.px2rem = function (d) {
var val = parseFloat(d) / this.rem
if (typeof d === 'string' && d.match(/px$/)) {
val += 'rem'
}
return val
}
})(window, window['lib'] || (window['lib'] = {}))
