Vue2.0实现自适应分辨率

import '@/utils/flexibleEx.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() {
    const whiteList = [
      '/managementKanban',
      '/productionKanban',
      '/controlBoard',
      '/main'
    ] // 不重定向白名单路由
    var width = docEl.getBoundingClientRect().width
    var rem = 0
 
    var hrefList = window.location.href.split('/')
    var url = hrefList[hrefList.length - 1]
    var url0 = url.split('?')
    var urlEnd
    if (url0.length > 0) {
      urlEnd = url0[0]
    }
    if (!whiteList.includes('/' + urlEnd)) {
      if (width / dpr <= 1980 && width / dpr > 768) {
        width = 1980 * dpr
        rem = width / 48
      } else if (width / dpr >= 5760) {
        width = 5760 * dpr
        rem = width / 48
      } else {
        width = 540 * dpr
        rem = width / 20
      }
      docEl.style.fontSize = rem + 'px'
      flexible.rem = win.rem = rem
    }
  }
 
  win.addEventListener(
    'resize',
    function() {
      clearTimeout(tid)
      tid = setTimeout(refreshRem, 300)
    },
    false
  )
  win.addEventListener(
    'DOMNodeInserted',
    function() {
      clearTimeout(tid)
      tid = setTimeout(refreshRem, 50)
    },
    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'] = {}))

function generateLoaders(loader, loaderOptions) {
    const loaders = options.usePostCSS ? [cssLoader] : [cssLoader];
 
    if (loader) {
      loaders.push({
        loader: loader + "-loader",
        options: Object.assign({}, loaderOptions, {
          sourceMap: options.sourceMap
        })
      });
    }
 
    // Extract CSS when that option is specified
    // (which is the case during production build)
    if (options.extract) {
      return ExtractTextPlugin.extract({
        use: loaders,
        fallback: "vue-style-loader",
        publicPath: "../../"
      });
    } else {
      return ["vue-style-loader"].concat(loaders);
    }
  }

module.exports = {
    plugins: {
        'autoprefixer': {
            overrideBrowserslist: [
                'Android 4.1',
                'iOS 7.1',
                'Chrome > 31',
                'ff > 31',
                'ie >= 8'
            ]
        },
        'postcss-pxtorem': {
            rootValue: 37.5,
            propList: ['*']
        }
    }
}