! function(win) { function resize() { var deviceWidth = document.documentElement.clientWidth; if(deviceWidth > 750) deviceWidth = 750; document.documentElement.style.fontSize = Math.floor(deviceWidth / 7.5) + 'px'; } var v, initial_scale, timeCode, dom = win.document, domEle = dom.documentElement, viewport = dom.querySelector('meta[name="viewport"]'), flexible = dom.querySelector('meta[name="flexible"]'); if(viewport) { //viewport: var o = viewport.getAttribute("content").match(/initial\-scale=(["']?)([\d\.]+)\1?/); if(o) { initial_scale = parseFloat(o[2]); v = parseInt(1 / initial_scale); } } else { if(flexible) { var o = flexible.getAttribute("content").match(/initial\-dpr=(["']?)([\d\.]+)\1?/); if(o) { v = parseFloat(o[2]); initial_scale = parseFloat((1 / v).toFixed(2)) } } } if(!v && !initial_scale) { var n = (win.navigator.appVersion.match(/android/gi), win.navigator.appVersion.match(/iphone/gi)); v = win.devicePixelRatio; v = n ? v >= 3 ? 3 : v >= 2 ? 2 : 1 : 1, initial_scale = 1 / v } //没有viewport标签的情况下 if(domEle.setAttribute("data-dpr", v), !viewport) { if(viewport = dom.createElement("meta"), viewport.setAttribute("name", "viewport"), viewport.setAttribute("content", "initial-scale=" + initial_scale + ", maximum-scale=" + initial_scale + ", minimum-scale=" + initial_scale + ", user-scalable=no"), domEle.firstElementChild) { domEle.firstElementChild.appendChild(viewport) } else { var m = dom.createElement("div"); m.appendChild(viewport), dom.write(m.innerHTML) } } win.dpr = v; win.addEventListener("resize", function() { clearTimeout(timeCode), timeCode = setTimeout(resize, 300) }, false); win.addEventListener("pageshow", function(b) { b.persisted && (clearTimeout(timeCode), timeCode = setTimeout(resize, 300)) }, false); /* 个人觉得没必要完成后就把body的字体设置为12 "complete" === dom.readyState ? dom.body.style.fontSize = 12 * v + "px" : dom.addEventListener("DOMContentLoaded", function() { //dom.body.style.fontSize = 12 * v + "px" }, false); */ resize(); }(window);