rem 适配
Posted freeman_Tian
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// 基准大小
const baseSize = 50
export function getClientW() {
let htmlWidth = document.documentElement.clientWidth || document.body.clientWidth;
if (htmlWidth > 768) {
htmlWidth = 768
}
if (htmlWidth < 320) {
htmlWidth = 320
}
// console.log(htmlWidth);
return htmlWidth
}
//计算根节点 字体大小 自适应 remy
function setRem(normalWidth = 375) {
const size = getClientW() / normalWidth * baseSize
document.body.style.fontSize = size + \'px\'
let htmlDom = document.getElementsByTagName(\'html\')[0]
htmlDom.style.fontSize = size + \'px\'
return size
}
// 初始化
setRem()
// 改变窗口大小时重新设置 rem
window.onresize = function () {
setRem()
};
//android微信中,借助WeixinJSBridge对象来阻止字体大小调整
(function () {
if (typeof WeixinJSBridge == "object" && typeof WeixinJSBridge.invoke == "function") {
handleFontSize();
} else {
if (document.addEventListener) {
document.addEventListener("WeixinJSBridgeReady", handleFontSize, false);
} else if (document.attachEvent) {
//IE浏览器,非W3C规范
document.attachEvent("onWeixinJSBridgeReady", handleFontSize);
}
}
function handleFontSize() {
// 设置网页字体为默认大小
WeixinJSBridge.invoke(\'setFontSizeCallback\', {
\'fontSize\': 0
});
// 重写设置网页字体大小的事件
WeixinJSBridge.on(\'menu:setfont\', function () {
WeixinJSBridge.invoke(\'setFontSizeCallback\', {
\'fontSize\': 0
});
});
}
})();
(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")
// eslint-disable-next-line no-useless-escape
.match(/initial\\-scale=([\\d\\.]+)/);
if (match) {
scale = parseFloat(match[1]);
dpr = parseInt(1 / scale);
}
} else if (flexibleEl) {
var content = flexibleEl.getAttribute("content");
if (content) {
// eslint-disable-next-line no-useless-escape
var initialDpr = content.match(/initial\\-dpr=([\\d\\.]+)/);
// eslint-disable-next-line no-useless-escape
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) {
// eslint-disable-next-line no-unused-vars
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;
// // 最小1366px,最大适配2560px
// if (width / dpr < 1366) {
// width = 1366 * dpr;
// } else if (width / dpr > 2560) {
// width = 2560 * dpr;
// }
// // 设置成24等份,设计稿时1920px的,这样1rem就是80px
// var rem = width / 24;
// docEl.style.fontSize = rem + "px";
// flexible.rem = win.rem = rem;
// }
function refreshRem() {
var baseSize = 100;
let basePc = baseSize / 1920; // 表示1920的设计图,使用100PX的默认值
let vW = window.innerWidth; // 当前窗口的宽度
let vH = window.innerHeight; // 当前窗口的高度
// 非正常屏幕下的尺寸换算
let dueH = vW * 1080 / 1920
if (vH < dueH) { // 当前屏幕高度小于应有的屏幕高度,就需要根据当前屏幕高度重新计算屏幕宽度
vW = vH * 1920 /1080
}
let rem = vW * basePc; // 以默认比例值乘以当前窗口宽度,得到该宽度下的相应font-size值
document.documentElement.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",
// eslint-disable-next-line no-unused-vars
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"] = {}));
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