风云际 2005-1-14 10:48
黑白渐变背景
将下列代码复制到<body></body>之间：<br>
<SCRIPT LANGUAGE="JavaScript"><br>
<!--<br>
<br>
function toHex(dec) {<br>
// create list of hex characters<br>
var hexCharacters = "0123456789ABCDEF"<br>
// if number is out of range return limit<br>
if (dec < 0)<br>
return "00"<br>
if (dec > 255)<br>
return "FF"<br>
// decimal equivalent of first hex character in converted number<br>
var i = Math.floor(dec / 16)<br>
// decimal equivalent of second hex character in converted number<br>
var j = dec % 16<br>
// return hexadecimal equivalent<br>
return hexCharacters.charAt(i) + hexCharacters.charAt(j)<br>
}<br>
// set background color to specified descriptors<br>
function setbgColor(red, green, blue) {<br>
document.bgColor = "#" + toHex(red) + toHex(green) + toHex(blue)<br>
}<br>
// fade from start to end descriptors (increase step to increase transition speed)<br>
function fade(sred, sgreen, sblue, ered, egreen, eblue, step) {<br>
// loop to create fade effect<br>
for(var i = 0; i <= step; ++i) {<br>
// set current red descriptor<br>
var red = Math.floor(sred * ((step - i) / step) + ered * (i / step))<br>
// set current green descriptor<br>
var green = Math.floor(sgreen * ((step - i) / step) + egreen * (i / step))<br>
// set current green descriptor<br>
var blue = Math.floor(sblue * ((step - i) / step) + eblue * (i / step))<br>
// set background color according to descriptors<br>
setbgColor(red, green, blue)<br>
}<br>
}<br>
// --><br>
</SCRIPT><br>
<BODY onLoad="fade(0, 0, 0, 255, 255, 255, 64)" onUnload="fade(255, 255, 255, 0, 0, 0, 64)">
