网易移动端适配

//网易移动端适配
;
(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");
if (!!win.webPageScalable) {
metaEl.setAttribute("content", "initial-scale=" + scale + ", user-scalable=yes")
} else {
metaEl.setAttribute("content", "initial-scale=" + scale + ", maximum-scale=" + scale + ", minimum-scale=" + scale + ", user-scalable=no viewport-fit=cover")
}
if (docEl.firstElementChild) {
docEl.firstElementChild.appendChild(metaEl)
} else {
var wrap = doc.createElement("div");
wrap.appendChild(metaEl);
doc.write(wrap.innerHTML)
}
}