main.js中
import 'lib-flexible/flexible'import './utils/flexible'
flexible.js
;(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) { // iOS下，对于2和3的屏，用2倍的方案，其余的用1倍方案 if (devicePixelRatio >= 3 && (!dpr || dpr >= 3)) { dpr = 3 } else if (devicePixelRatio >= 2 && (!dpr || dpr >= 2)) { dpr = 2 } else { dpr = 1 } } else { // 其他设备下，仍旧使用1倍的方案 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 > 540) { width = width * dpr } let flag = win.navigator.userAgent.match( /(phone|pad|pod|iPhone|iPod|ios|iPad|Android|Mobile|BlackBerry|IEMobile|MQQBrowser|JUC|Fennec|wOSBrowser|BrowserNG|WebOS|Symbian|Windows Phone)/i ) var rem if (flag === null) { rem = width / 45 } else { rem = (width / 55) * 5.5 } 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'] = {}))
