flexible.js在華某爲手機上使用rem時，頁面寬度超出手機屏幕寬度

問題：手機端項目在華爲的某款手機上顯示時頁面內容沒有自適應手機寬度，出現橫向滾動條

緣由：手機獲取手機屏幕寬度並計算出rem時出現誤差，明顯寬餘真實手機屏寬度

解決方案一：在頁面裏獲取頁面最外層dom的寬度即html的寬度與手機屏幕的寬度對比，若是二者不等，直接給html的font-size設置成真實手機寬度的rem,解決問題，簡單粗暴，但我女友不喜歡我簡單粗暴，喜歡溫柔的，so~

解決方案二：修改flexible.js

改變部分：

// 處理不規則的rem計算
function fixFontSize(width, rem, html)
{ var html= doc.getElementsByTagName('html')[0];
var scale = 1;
var bodyWidth = parseInt(html.offsetWidth);
if (bodyWidth != width) {
scale = width / bodyWidth;
rem = rem * scale; docEl.style.fontSize = rem + 'px';
}
body.style.width = '100%'; }



    function refreshRem(){
        var width = docEl.getBoundingClientRect().width;
var hwidth = doc.docEl?doc.doeEl.clientWidth:doc.body.clientWidth
        if (width / dpr > 540) {
            width = 540 * dpr;
        }
        var rem = width / 10;
        docEl.style.fontSize = rem + 'px';
        flexible.rem = win.rem = rem;
fixFontSize(hwidth,rem)
    }

完整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('將根據已有的meta標籤來設置縮放比例');
        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，對於2和3的屏，用2倍的方案，其他的用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 {
            // 其餘設備下，仍舊使用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);
        }
    }

// 處理不規則的rem計算

function fixFontSize(width, rem, html)

{ var html= doc.getElementsByTagName('html')[0];

var scale = 1;

var bodyWidth = parseInt(html.offsetWidth);

if (bodyWidth != width) {

scale = width / bodyWidth;

rem = rem * scale; docEl.style.fontSize = rem + 'px';

}

body.style.width = '100%'; }

    function refreshRem(){
        var width = docEl.getBoundingClientRect().width;
var hwidth = doc.docEl?doc.doeEl.clientWidth:doc.body.clientWidth
        if (width / dpr > 540) {
            width = 540 * dpr;
        }
        var rem = width / 10;
        docEl.style.fontSize = rem + 'px';
        flexible.rem = win.rem = rem;
fixFontSize(hwidth,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'] = {}));