javascript 操作 css Rule

 //add   addCssRule('.bcd',{'color':'red','font-weight':'bold','font-size':'12px'},document.styleSheets[1]);
     function addCssRule(selector,styles,styleSheet,index){
         var sheets = styleSheet instanceof Array ? styleSheet : [styleSheet],
             style = '',
             declaration = '';
         for(var pro in styles){
             if(styles.hasOwnProperty(pro)){
                 declaration += (pro + ':' + styles[pro] + ';');
             }
         }
         style = selector + '{' + declaration + '}';
         for(var i = 0,j = sheets.length; i < j;i++){
             if(sheets[i].insertRule){
                 index = index >= 0 ? index : sheets[i]['cssRules'].length;
                 sheets[i].insertRule(style,index);
             }else if(sheets[i].addRule){  //IE
                 index = index >= 0 ? index : -1;  //-1为末尾
                 sheets[i].addRule(selector,declaration,index);
             }
         }
     }

     //modify   editCssRule('.abc',{'font-weight':'bold','font-size':'14px'},document.styleSheets[1]);
     function editCssRule(selector,styles,styleSheet){
         var sheets = styleSheet instanceof Array ? styleSheet : [styleSheet];
         selector = selector.toUpperCase(); // ie9以下标签选择器默认是大写   这里统一下
         //对大小写敏感的selector 会有问题
         for(var i = 0,j = sheets.length; i < j;i++){
             var rules = sheets[i]['cssRules'] || sheets[i]['rules'];   //ie为 rules
             if(!rules){ continue;}
             for(var m = 0,n = rules.length;m < n;m++){
                 if(rules[m]['selectorText'].toUpperCase() == selector){
                     for(var pro in styles){
                         if(styles.hasOwnProperty(pro)){
                             rules[m].style[cssCamilize(pro)] = styles[pro];
                         }
                     }
                 }
             }
         }
     }

     //del   delCssRule('.bcd',document.styleSheets[1]);
     function delCssRule(selector,styleSheet,index){
         var sheets = styleSheet instanceof Array ? styleSheet : [styleSheet];
         selector = selector.toUpperCase();
         for(var i = 0,j = sheets.length; i < j;i++){
             var rules = sheets[i]['cssRules'] || sheets[i]['rules'];   //ie为 rules
             if(index >=0 && index < rules.length){
                 sheets[i].deleteRule ? sheets[i].deleteRule(index) : sheets[i].removeRule(index);
             }else if(selector){
                for(var m = 0,n = rules.length;m < n;m++){
                     if(rules[m]['selectorText'].toUpperCase() == selector){
                        sheets[i].deleteRule ? sheets[i].deleteRule(m) : sheets[i].removeRule(m);;  //可能存在多个一样的selector  全部删除
                     }
                 }
             }else{
                 return false;
             }
         }
     };

 function cssCamilize(str){
         return str.replace(/-(\w)/g,function($1,$2){
             return $2.toUpperCase();
         });
     };

//参考：http://www.cnblogs.com/2050/p/4029656.html
function addCSS(cssText){
    var style = document.createElement('style'),  //创建一个style元素
        head = document.head || document.getElementsByTagName('head')[0]; //获取head元素
    style.type = 'text/css'; //这里必须显示设置style元素的type属性为text/css，否则在ie中不起作用
    if(style.styleSheet){ //IE
        var func = function(){
            try{ //防止IE中stylesheet数量超过限制而发生错误
                style.styleSheet.cssText = cssText;
            }catch(e){

            }
        }
        //如果当前styleSheet还不能用，则放到异步中则行
        if(style.styleSheet.disabled){
            setTimeout(func,10);
        }else{
            func();
        }
    }else{ //w3c
        //w3c浏览器中只要创建文本节点插入到style元素中就行了
        var textNode = document.createTextNode(cssText);
        style.appendChild(textNode);
    }
    head.appendChild(style); //把创建的style元素插入到head中
}