Jquery作者John Resig自己封装的javascript 常用函数
//获取元素的样式值。function getStyle(elem,name){ if(elem.style[name]){ return elem.style[name]; }else if(elem.currentStyle){ return elem.currentStyle[name]; }else if(document.defaultView&&document.defaultView.getComputedStyle){ name=name.replace(/([A-Z])/g,"-$1"); name=name.toLowerCase(); var s=document.defaultView.getComputedStyle(elem,""); return s&&s.getPropertyValue(name); }else{ return null }}//获取元素相对于这个页面的x和y坐标。 function pageX(elem){ return elem.offsetParent?(elem.offsetLeft+pageX(elem.offsetParent)):elem.offsetLeft;}function pageY(elem){ return elem.offsetParent?(elem.offsetTop+pageY(elem.offsetParent)):elem.offsetTop;}//获取元素相对于父元素的x和y坐标。 function parentX(elem){ return elem.parentNode==elem.offsetParent?elem.offsetLeft:pageX(elem)-pageX(elem.parentNode);}function parentY(elem){ return elem.parentNode==elem.offsetParent?elem.offsetTop:pageY(elem)-pageY(elem.parentNode);}//获取使用css定位的元素的x和y坐标。function posX(elem){ return parseInt(getStyle(elem,"left"));} function posY(elem){ return parseInt(getStyle(elem,"top"));}//设置元素位置。 function setX(elem,pos){ elem.style.left=pos+"px";} function setY(elem,pos){ elem.style.top=pos+"px";}//增加元素X和y坐标。 function addX(elem,pos){ set(elem,(posX(elem)+pos));}function addY(elem,pos){ set(elem,(posY(elem)+pos));}//获取元素使用css控制大小的高度和宽度 function getHeight(elem){ return parseInt(getStyle(elem,"height"));}function getWidth(elem){ return parseInt(getStyle(elem,"width"));}//获取元素可能，完整的高度和宽度function getFullHeight(elem){ if(getStyle(elem,"display")!="none"){ return getHeight(elem)||elem.offsetHeight; }else{ var old=resetCss(elem,{display:"block",visibility:"hidden",position:"absolute"}); var h=elem.clientHeight||getHeight(elem); restoreCss(elem,old); return h; }}function getFullWidth(elem){ if(getStyle(elem,"display")!="none"){ return getWidth(elem)||elem.offsetWidth; }else{ var old=resetCss(elem,{display:"block",visibility:"hidden",position:"absolute"}); var w=elem.clientWidth||getWidth(elem); restoreCss(elem,old); return w; }}//设置css，并保存旧的cssfunction resetCss(elem,prop){ var old={}; for(var i in prop){ old[i]=elem.style[i]; elem.style[i]=prop[i]; } return old;}function restoreCss(elem,prop){ for(var i in prop){ elem.style[i]=prop[i]; }}//显示和隐藏function show(elem){ elem.style.display=elem.$oldDisplay||"";}function hide(elem){ var curDisplay=getStyle(elem,"display"); if(curDisplay!="none"){ elem.$oldDisplay=curDisplay; elem.style.display="none"; }}//设置透明度 setOpacity(elem,40)function setOpacity(elem,num){ if(elem.filters){ elem.style.filter="alpha(opacity="+num+")"; }else{ elem.style.opacity=num/100; }}//滑动function slideDown(elem){ var h=getFullHeight(elem); elem.style.height="0px"; show(elem); for(var i=0;i<=100;i+=5){ new function(){ var pos=i; setTimeout(function(){elem.style.height=(pos/100*h)+"px";},(pos*10)); } }}//渐变function fadeIn(elem){ show(elem); setOpacity(elem,0); for(var i=0;i<=100;i+=5){ new function(){ var pos=i; setTimeout(function(){setOpacity(elem,pos);},(pos+1)*10); } } }//获取鼠标光标相对于整个页面的位置。 function getX(e){ e=e||window.event; return e.pageX||e.clientX+document.body.scrollLeft; }function getY(e){ e=e||window.event; return e.pageY||e.clientY+document.body.scrollTop; }//获取鼠标光标相对于当前元素的位置。function getElementX(e){ return (e&&e.layerX)||window.event.offsetX; }function getElementY(e){ return (e&&e.layerY)||window.event.offsetY; }//获取页面的高度和宽度function getPageHeight(){ var de=document.documentElement; return document.body.scrollHeight||(de&&de.scrollHeight); }function getPageWidth(){ var de=document.documentElement; return document.body.scrollWidth||(de&&de.scrollWidth); }//获取滚动条的位置。function scrollX(){ var de=document.documentElement; return self.pageXOffset||(de&&de.scrollLeft)||document.body.scrollLeft; }function scrollY(){ var de=document.documentElement; return self.pageYOffset||(de&&de.scrollTop)||document.body.scrollTop; }//获取视口的高度和宽度。function windowHeight() { var de = document.documentElement; return self.innerHeight||(de && de.offsetHeight)||document.body.offsetHeight;}function windowWidth() { var de = document.documentElement; return self.innerWidth||( de && de.offsetWidth )||document.body.offsetWidth;}?[转自:http://www.jb51.net/article/20809.htm]