<script> //designWidth:设计稿的实际宽度值,需要根据实际设置 //maxWidth:制作稿的最大宽度值,需要根据实际设置 //这段js的最后面有两个参数记得要设置,一个为设计稿实际宽度,一个为制作稿最大宽度,例如设计稿为750,最大宽度为750,则为(750,750) ; (function (designWidth, maxWidth) { var doc = document, win = window, docEl = doc.documentElement, remStyle = document.createElement("style"), tid; function refreshRem() { var width = docEl.getBoundingClientRect().width; maxWidth = maxWidth || 540; width > maxWidth && (width = maxWidth); var rem = width * 100 / designWidth; remStyle.innerHTML = 'html{font-size:' + rem + 'px !important;}'; } if (docEl.firstElementChild) { docEl.firstElementChild.appendChild(remStyle); } else { var wrap = doc.createElement("div"); wrap.appendChild(remStyle); doc.write(wrap.innerHTML); wrap = null; } //要等 wiewport 设置好后才能执行 refreshRem,不然 refreshRem 会执行2次; refreshRem(); win.addEventListener("resize", function () { clearTimeout(tid); //防止执行两次 tid = setTimeout(refreshRem, 300); }, false); win.addEventListener("pageshow", function (e) { if (e.persisted) { // 浏览器后退的时候重新计算 clearTimeout(tid); tid = setTimeout(refreshRem, 300); } }, false); if (doc.readyState === "complete") { doc.body.style.fontSize = "16px"; } else { doc.addEventListener("DOMContentLoaded", function (e) { doc.body.style.fontSize = "16px"; }, false); } })(750, 750); </script> //压缩以后的 <script type="text/javascript"> //引入该flexible.min.js !function (e, t) { function n() { var n = l.getBoundingClientRect().width; t = t || 540, n > t && (n = t); var i = 100 * n / e; r.innerHTML = "html{font-size:" + i + "px !important;}" } var i, d = document, o = window, l = d.documentElement, r = document.createElement("style"); if (l.firstElementChild) l.firstElementChild.appendChild(r); else { var a = d.createElement("div"); a.appendChild(r), d.write(a.innerHTML), a = null } n(), o.addEventListener("resize", function () { clearTimeout(i), i = setTimeout(n, 300) }, !1), o.addEventListener("pageshow", function (e) { e.persisted && (clearTimeout(i), i = setTimeout(n, 300)) }, !1), "complete" === d.readyState ? d.body.style.fontSize = "16px" : d.addEventListener("DOMContentLoaded", function (e) { d.body.style.fontSize = "16px" }, !1) }(750, 750); </script>
复制压缩后的JS到 header 之间,不要当文件引入。
然后本页面的 px 就能换成 rem,保证不同屏幕下效果一致