转载

移动web适配方案动态计算版

以前整理过一篇移动端适配方案的文章,当时是在部门的专题cms系统中使用。文章地址

思路就是通过媒介查询整理出一套根字体大小,然后各个元素通过rem单位来进行适配。

而这次我们的根字体大小不再是通过媒介查询得到,而是通过屏幕宽度进行动态计算,并且还具有高分辨率屏幕的兼容性处理。

废话不多说,直接上源码

好的知识当然需要大家一起共享才快乐。在此公开源码,方便大家共同进步。

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('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'] = {}));

scss部分:

/* 字体 */

@mixin font-dpr($font-size) {
font-size: $font-size;
[data-dpr="2"] & {
font-size: $font-size * 2;
}
[data-dpr="3"] & {
font-size: $font-size * 3;
}
}


/* rem */
/* 我们项目的视觉稿为750px */
$rem-baseline: 75px !default;
@function rem-separator($list) {
@if function-exists("list-separator")==true {
@return list-separator($list);
}
$test-list: ();
@each $item in $list {
$test-list: append($test-list, $item, space);
}
@return if($test-list==$list, space, comma);
}

@mixin rem-baseline($zoom: 100%) {
font-size: $zoom / 16px * $rem-baseline;
}

@function rem-convert($to, $values...) {
$result: ();
$separator: rem-separator($values);
@each $value in $values {
@if type-of($value)=="number" and unit($value)=="rem" and $to=="px" {
$result: append($result, $value / 1rem * $rem-baseline, $separator);
}
@else if type-of($value)=="number" and unit($value)=="px" and $to=="rem" {
$result: append($result, $value / ($rem-baseline / 1rem), $separator);
}
@else if type-of($value)=="list" {
$result: append($result, rem-convert($to, $value...), $separator);
}
@else {
$result: append($result, $value, $separator);
}
}
@return if(length($result)==1, nth($result, 1), $result);
}

@function px2rem($values...) {
//@if $rem-px-only {
// @return rem-convert(px, $values...);
//} @else {
@return rem-convert(rem, $values...);
//}
}

@mixin px2rem($properties, $values...) {
@if type-of($properties)=="map" {
@each $property in map-keys($properties) {
@include px2rem($property, map-get($properties, $property));
}
}
@else {
@each $property in $properties {
//@if $rem-fallback or $rem-px-only {
// #{$property}: rem-convert(px, $values...);
//}
//@if not $rem-px-only {
#{$property}: rem-convert(rem, $values...);
//}
}
}
}

使用方式:

.m-banner {
height: px2rem(640px);
&-introduction {
margin:0 auto;
padding:px2rem(110px) 0 px2rem(40px) 0;
width: px2rem(660px);
font-size: px2rem(66px);
line-height: px2rem(90px);
text-align: center;
}
&-detailDescription {
margin: 0 auto;
width: px2rem(660px);
font-size: px2rem(24px);
line-height: px2rem(36px);
text-align: center;
}
&-video {
left: 50%;
margin: px2rem(60px) 0 0 px2rem(-50px);
width: px2rem(100px);
height: px2rem(100px);
background: url(http://nos.netease.com/edu-image/3AB7C15D5AF4FD7C573E34D05535F5F8.png) no-repeat;
background-size: 100%;
}
}
原文  http://brizer.github.io/2016/08/20/移动web适配方案动态计算版/
正文到此结束
Loading...