如何通过JS实现颜色实时渐变效果?

如何通过JS实现颜色实时渐变效果?

本文实例讲述了JS实现的颜色实时渐变效果。分享给大家供大家参考,具体如下:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>无标题页</title>
</head>
<body>
<div id="div1" style="font-size:36px;">我的闪烁文字 abc123</div>
<span id="span1"></span>
<script type="text/javascript">
var begin = getRGB('#33FFAA');
var end = getRGB('#FF0000');
var curColor = getRGB('#33FFAA');
var bo = true;
var rate = getRate(begin, end);
function blink()
{
 window.setInterval(function(){
  curColor.r = getCur(begin.r, end.r, curColor.r, bo, rate.r);
  curColor.g = getCur(begin.g, end.g, curColor.g, bo, rate.g);
  curColor.b = getCur(begin.b, end.b, curColor.b, bo, rate.b);
  document.getElementById('div1').style.color = getColor(curColor);
  document.getElementById('span1').innerHTML = getColor(curColor);
  if(curColor.r == begin.r && curColor.g == begin.g && curColor.b == begin.b)
  {
   bo = true;
  }
  if(curColor.r == end.r && curColor.g == end.g && curColor.b == end.b)
  {
   bo = false;
  }
 } , 100);
}
function getCur(beginValue, endValue, curValue, bo, rateValue)
{
 if(beginValue == endValue)
 {
  return beginValue;
 }
 rateValue = beginValue < endValue ? rateValue : -rateValue;
 curValue += bo ? rateValue : -rateValue;
 if(curValue < Math.min(beginValue, endValue))
 {
  curValue = Math.min(beginValue, endValue);
 }
 if(curValue > Math.max(beginValue, endValue))
 {
  curValue = Math.max(beginValue, endValue);
 }
 return curValue;
}
function getRate(b, e)
{
 var obj = new Object();
 obj.r = Math.abs(b.r - e.r) / 5;
 obj.g = Math.abs(b.g - e.g) / 5;
 obj.b = Math.abs(b.b - e.b) / 5;
 return obj;
}
function getRGB(color)
{
 var obj = new Object();
 obj.r = parseInt(color.substr(1,2), 16);
 obj.g = parseInt(color.substr(3,2), 16);
 obj.b = parseInt(color.substr(5,2), 16);
 return obj;
}
function getColor(obj)
{
 obj.r = Math.round(obj.r);
 obj.g = Math.round(obj.g);
 obj.b = Math.round(obj.b);
 var color = '#';
 color += (obj.r < 16 ? '0':'') + obj.r.toString(16);
 color += (obj.g < 16 ? '0':'') + obj.g.toString(16);
 color += (obj.b < 16 ? '0':'') + obj.b.toString(16);
 return color;
}
blink();
</script>
</body>
</html>

希望本文所述对大家JavaScript程序设计有所帮助。