内联样式的获取
function getStyle(obj,attr){//简单的获取内联样式
return obj.currentStyle?obj.currentStyle[attr]:obj.getComputedStyle(obj,false)[attr];
}
下面是比较完善的，
//参考地址 http://stylechen.com/getstyle2.html
var getStyle = function( elem, style ){ //单位如果em或%的单位，getComputedStyle()返回的值就会自动将em或%换成px的单位，currentStyle就不会，而如果是font-size使用em为单位，在Opera下返回的是0em，Opera真的很恐怖！
return 'getComputedStyle' in window ?
getComputedStyle( elem, null )[style] :
function(){
style = style.replace( /\-(\w)/g, function( $, $1 ){
return $1.toUpperCase();
});
var val = elem.currentStyle[style];
if( val === 'auto' && (style === "width" || style === "height") ){
var rect = elem.getBoundingClientRect();
if( style === "width" ){
return rect.right - rect.left + 'px';
}else{
return rect.bottom - rect.top + 'px';
}
}
return val;
}();
};
// 调用该方法
//var test = document.getElementById( 'test' ),
// 获取计算的宽度
//tWidth = getStyle( test, 'width' );
原生获取className
function getClass(parent,className,tagName){
//var parent = parent || document,
var parent = !!(parent != undefined&&parent.nodeType==1)?parent:document, //parent参数是可选的，但需要先判断它是否存在，且是节点dom元素 parent != undefined&&parent.nodeType==1 ，nodeType == 1可以判断节点是否为dom元素，在火狐浏览器里面，空白也算是节点（.childnodes），用这个属性就判断是否为dom元素，排除空白符.
tagName = tagName || "*"; //alert(parent.nodeName); //ul
if(parent.getElementsByClassName){
return parent.getElementsByClassName(className);
}else{
var aEls =parent.getElementsByTagName(tagName),arr = [],re=new RegExp('(^|\\s)'+className+'($|\\s)');
for (var i = 0; i < aEls.length; i++) {
re.test(aEls[i].className) && arr.push(aEls[i]);
};
return arr;
};
} ; //获取class (因为获取一组元素集合，如果单个使用一定要加[0]下标，不然会报错)
添加样式
function addClass(ele,cls) {
if (!this.hasClass(ele,cls)) ele.className += " "+cls;
}
另外一种比较好的
function addclass(elm,cls){ // 参考地址 ：http://www.ghugo.com/transfer-should-have-known-7-javascript-skills/
var classes = elm.className.split(' ');
classes.push(cls);
elm.className = classes.join(' ');
}
已有样式
function hasClass(ele,cls) {
return ele.className.match(new RegExp('(\\s|^)'+cls+'(\\s|$)'));}
移除样式
function removeClass(ele,cls) {
if (hasClass(ele,cls)) {
var reg = new RegExp('(\\s|^)'+cls+'(\\s|$)');
ele.className=ele.className.replace(reg,' ');
}
}
以上是利用了原生js对样式的操作获取
Html5新增的api接口，
<script>
/*!
* classie - class helper functions
* from bonzo https://github.com/ded/bonzo
*
* classie.has( elem, 'my-class' ) -> true/false
* classie.add( elem, 'my-new-class' )
* classie.remove( elem, 'my-unwanted-class' )
* classie.toggle( elem, 'my-class' )
*/ /*jshint browser: true, strict: true, undef: true */
/*global define: false */ ;( function( window ) { 'use strict'; // class helper functions from bonzo https://github.com/ded/bonzo function classReg( className ) {
return new RegExp("(^|\\s+)" + className + "(\\s+|$)");
} // classList support for class management
// altho to be fair, the api sucks because it won't accept multiple classes at once
var hasClass, addClass, removeClass; if ( 'classList' in document.documentElement ) {
hasClass = function( elem, c ) {
return elem.classList.contains( c );
};
addClass = function( elem, c ) {
elem.classList.add( c );
};
removeClass = function( elem, c ) {
elem.classList.remove( c );
};
}
else {
hasClass = function( elem, c ) {
return classReg( c ).test( elem.className );
};
addClass = function( elem, c ) {
if ( !hasClass( elem, c ) ) {
elem.className = elem.className + ' ' + c;
}
};
removeClass = function( elem, c ) {
elem.className = elem.className.replace( classReg( c ), ' ' );
};
} function toggleClass( elem, c ) {
var fn = hasClass( elem, c ) ? removeClass : addClass;
fn( elem, c );
} var classie = {
// full names
hasClass: hasClass,
addClass: addClass,
removeClass: removeClass,
toggleClass: toggleClass,
// short names
has: hasClass,
add: addClass,
remove: removeClass,
toggle: toggleClass
}; // transport
if ( typeof define === 'function' && define.amd ) {
// AMD
define( classie );
} else {
// browser global
window.classie = classie;
} })( window );
</script>
以上的缺点：只能添加单个样式 elem.classList.add( classNameOne ); 需要自己完善