移动端设置字体px转换rem的脚本

(function (){
           var _self = this;
           _self.width = 640;//设置默认最大宽度
           _self.fontSize = 100;//默认字体大小
           _self.widthProportion = function(){var p = (document.body&&document.body.clientWidth||document.getElementsByTagName("html")[0].offsetWidth)/_self.width;return p>1?1:p<0?0:p;};
           _self.changePage = function(){
               document.getElementsByTagName("html")[0].setAttribute("style","font-size:"+_self.widthProportion()*_self.fontSize+"px !important");
           }
           _self.changePage();
           window.addEventListener('resize',function(){_self.changePage();},false);
        })();