flexble的官网地址：http://yunkus.com/mobile-adaptation-scheme-flexiblejs/

2.vue适配移动端的配置链接 lib-flexible.js

https://blog.csdn.net/Coding_Jia/article/details/78866220

1.flexble的作用

 正如文章标题所写的那样，它就是一个终端设备适配的解决方案。
 也就是说它可以让你在不同的终端设备中实现页面适配。

2.flexble.js的用法

直接在头部标签引用flexble.css / flexble.js 文件
<script src="http://g.tbcdn.cn/mtb/lib-flexible/0.3.4/??flexible_css.js,flexible.js"></script>

3.flexble的css文件

@charset "utf-8";
html{color:#000;background:#fff;overflow-y:scroll;-webkit-text-size-adjust:100%;-ms-text-size-adjust:100%}
html *{outline:0;-webkit-text-size-adjust:none;-webkit-tap-highlight-color:rgba(0,0,0,0)}
html,body{font-family:sans-serif}
body,div,dl,dt,dd,ul,ol,li,h1,h2,h3,h4,h5,h6,pre,code,form,fieldset,legend,input,textarea,p,blockquote,th,td,hr,button,article,aside,details,figcaption,figure,footer,header,hgroup,menu,nav,section{margin:0;padding:0}
input,select,textarea{font-size:100%}
table{border-collapse:collapse;border-spacing:0}
fieldset,img{border:0}
abbr,acronym{border:0;font-variant:normal}
del{text-decoration:line-through}address,caption,cite,code,dfn,em,th,var{font-style:normal;font-weight:500}
ol,ul{list-style:none}
caption,th{text-align:left}
h1,h2,h3,h4,h5,h6{font-size:100%;font-weight:500}
q:before,q:after{content:''}
sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}
sup{top:-.5em}
sub{bottom:-.25em}
a:hover{text-decoration:underline}
ins,a{text-decoration:none}

4.flexble的js文件

;(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) {
            // 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;
        if (width / dpr > 540) {
            width = 540 * dpr;
        }
        var rem = width / 10;
        docEl.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', 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'] = {}));

1.移动端适配就是为了让不同的设备展示出来的内容是一样的，通俗的说

写移动端页面必须要配置就是meta

   <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <meta name="viewport" content="width=device-width,initial-scale=1.0,user-scalable=no,minimal-ui" />

2. 设计稿宽度/设备宽度=100/x 设备根元素字体大小 最简单的

      var desW=640;
       var winW=document.documentElement.clientWidth;/*设备宽度*/
       document.documentElement.style.fontSize=winW/desW*100+'px';

方法2

   <script type="text/javascript">
        (function (doc, win) {
            var docEl = doc.documentElement,
                    resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
                    recalc = function () {
                        var clientWidth = docEl.clientWidth;
                        if (!clientWidth) return;
                        if(clientWidth>=750){
                            docEl.style.fontSize = '100px';
                        }else{
                            docEl.style.fontSize = 100 * (clientWidth / 640) + 'px';
                        };
                    };
            if (!doc.addEventListener){ return};
            win.addEventListener(resizeEvt, recalc, false);
            doc.addEventListener('DOMContentLoaded', recalc, false);
        })(document, window);
    </script>

设置根字节为100px是因为好换算，设计稿是设备的2倍，所以如果在设计稿上量的100px的话，展示到设备上就是50px