JavaScript access controls external CSS and determines browser version

其实很多或者说大部分CSS文件对网页的描述都是以外部CSS的身份出现的，所以当需要做一些需要JS改变CSS而

出现的动态效果的时候，JS不得不去访问外部CSS，下面我们就来探讨一下JS访问外部CSS的例子。

这个例子就是点击按钮触发事件来改变DIV的背景颜色。首先请看CSS文件

[css]
.style1{ 
    width: 400px; 
    height: 500px; 
    background-color: red; 
} 
.style1{
 width: 400px;
 height: 500px;
 background-color: red;
}
然后是HTML文件

[html]
 
 
   
     
     
     
     
     
     
     
     
   
   
   

div1

 
     
    
  


 
    
   
 


 
   
 
   
   
   
   
   
   
 
 
  

div1

The first css

    var cssResult = document.styleSheets[0].rules;

                             
              if(eventObj.value==" Black"){
         style1.style.backgroundColor="black";      }
function test(eventObj){
//Get the content in mycss.css All class selectors
//This 0 means the first css introduced in the HTML page
var cssResult = document.styleSheets[0].rules;
//Get the specified CSS class selector according to the subscript
var style1 = cssResult[0];

if(eventObj.value=="black"){
style1.style.backgroundColor="black";
}else{
style1.style.backgroundColor="red";
}
}This function is, and its meaning has been introduced. It should be said that it is a good way to access external CSS. Of course, for browser compatibility, it is necessary to determine the browser version. The test1() function explains this , respectively, are judged by using the space support of the ActiveX window. In fact, there should be a more comprehensive one, and we will study it when we come back.