网页背景特效代码-星空背景
要完成此效果需要两个步骤
第一步：把如下代码加入到<body>区域中
<script language="JavaScript">
<!--
SmallStars = 30;
LargeStars = 10;
SmallYpos = new Array();
SmallXpos = new Array();
LargeYpos = new Array();
LargeXpos = new Array();
Smallspeed= new Array();
Largespeed= new Array();
ns=(document.layers)?1:0;
if (ns){
for (i = 0; i < SmallStars; i++)
{document.write("<LAYER NAME= sn"+i+" LEFT=0 TOP=0 BGCOLOR= #FFFFF0 CLIP= 0,0,1,1 ></LAYER>")}
for (i = 0; i < LargeStars; i++)
{document.write("<LAYER NAME= ln"+i+" LEFT=0 TOP=0 BGCOLOR= #FFFFFF CLIP= 0,0,2,2 ></LAYER>")}
}
else{
document.write( <div style="position:absolute;top:0px;left:0px"> );
document.write( <div style="position:relative"> );
for (i = 0; i < SmallStars; i++)
{document.write( <div id="si" style="position:absolute;top:0;left:0;width:1px;height:1px;background:#fffff0;font-size:1px"></div> )}
document.write( </div> );
document.write( </div> );
document.write( <div style="position:absolute;top:0px;left:0px"> );
document.write( <div style="position:relative"> );
for (i = 0; i < LargeStars; i++)
{document.write( <div id="li" style="position:absolute;top:0;left:0;width:2px;height:2px;background:#ffffff;font-size:2px"></div> )}
document.write( </div> );
document.write( </div> );
}
WinHeight=(document.layers)?window.innerHeight:window.document.body.clientHeight;
WinWidth=(document.layers)?window.innerWidth:window.document.body.clientWidth;
//Inital placement!
for (i=0; i < SmallStars; i++)
{
SmallYpos[i] = Math.round(Math.random()*WinHeight);
SmallXpos[i] = Math.round(Math.random()*WinWidth);
Smallspeed[i]= Math.random()*5+1;
}
for (i=0; i < LargeStars; i++)
{
LargeYpos[i] = Math.round(Math.random()*WinHeight);
LargeXpos[i] = Math.round(Math.random()*WinWidth);
Largespeed[i]= Math.random()*10+5;
}
function fly(){
var WinHeight=(document.layers)?window.innerHeight:window.document.body.clientHeight;
var WinWidth=(document.layers)?window.innerWidth:window.document.body.clientWidth;
var hscrll=(document.layers)?window.pageYOffset:document.body.scrollTop;
var wscrll=(document.layers)?window.pageXOffset:document.body.scrollLeft;
for (i=0; i < LargeStars; i++)
{
LargeXpos[i]-=Largespeed[i];
if (LargeXpos[i] < -10)
{
LargeXpos[i]=WinWidth;
LargeYpos[i]=Math.round(Math.random()*WinHeight);
Largespeed[i]=Math.random()*10+5;
}
if (ns){
document.layers[ ln +i].left=LargeXpos[i];
document.layers[ ln +i].top=LargeYpos[i]+hscrll;
}
else{
li[i].style.pixelLeft=LargeXpos[i];
li[i].style.pixelTop=LargeYpos[i]+hscrll;
}
}
for (i=0; i < SmallStars; i++)
{
SmallXpos[i]-=Smallspeed[i];
if (SmallXpos[i] < -10)
{
SmallXpos[i]=WinWidth;
SmallYpos[i]=Math.round(Math.random()*WinHeight);
Smallspeed[i]=Math.random()*5+1;
}
if (ns){
document.layers[ sn +i].left=SmallXpos[i];
document.layers[ sn +i].top=SmallYpos[i]+hscrll;
}
else{
si[i].style.pixelLeft=SmallXpos[i];
si[i].style.pixelTop=SmallYpos[i]+hscrll;
}
}
setTimeout( fly() ,10);
}
//fly();
//-->
</script>
第二步：把“onLoad="fly()"”加在<body>标记里
例如：<body onLoad="fly()">