<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>用 Javascript 实现锚点(Anchor)间平滑跳转</title>
<script language="javascript">
// 说明 ：用 Javascript 实现锚点(Anchor)间平滑跳转
// 转换为数字
function intval(v)
{
v = parseInt(v);
return isNaN(v) ? 0 : v;
}
// 获取元素信息
function getPos(e)
{
var l = 0;
var t = 0;
var w = intval(e.style.width);
var h = intval(e.style.height);
var wb = e.offsetWidth;
var hb = e.offsetHeight;
while (e.offsetParent)
{
l += e.offsetLeft + (e.currentStyle?intval(e.currentStyle.borderLeftWidth):0);
t += e.offsetTop + (e.currentStyle?intval(e.currentStyle.borderTopWidth):0);
e = e.offsetParent;
}
l += e.offsetLeft + (e.currentStyle?intval(e.currentStyle.borderLeftWidth):0);
t += e.offsetTop + (e.currentStyle?intval(e.currentStyle.borderTopWidth):0);
return {x:l, y:t, w:w, h:h, wb:wb, hb:hb}; }
// 获取滚动条信息
function getScroll()
{
var t, l, w, h;
if (document.documentElement && document.documentElement.scrollTop)
{
t = document.documentElement.scrollTop;
l = document.documentElement.scrollLeft;
w = document.documentElement.scrollWidth;
h = document.documentElement.scrollHeight;
}
else if (document.body)
{
t = document.body.scrollTop;
l = document.body.scrollLeft;
w = document.body.scrollWidth;
h = document.body.scrollHeight;
}
return { t: t, l: l, w: w, h: h };
}
// 锚点(Anchor)间平滑跳转
function scroller(el, duration)
{
if(typeof el != 'object')
{
el = document.getElementById(el);
}
if(!el) return;
var z = this;
z.el = el;
z.p = getPos(el);
z.s = getScroll();
z.clear = function()
{
window.clearInterval(z.timer);z.timer=null
};
z.t=(new Date).getTime();
z.step = function()
{
var t = (new Date).getTime();
var p = (t - z.t) / duration;
if (t >= duration + z.t)
{
z.clear();
window.setTimeout(function(){z.scroll(z.p.y, z.p.x)},13); }
else {
st = ((-Math.cos(p*Math.PI)/2) + 0.5) * (z.p.y-z.s.t) + z.s.t;
sl = ((-Math.cos(p*Math.PI)/2) + 0.5) * (z.p.x-z.s.l) + z.s.l;
z.scroll(st, sl);
}
};
z.scroll = function (t, l){window.scrollTo(l, t-20)};
z.timer = window.setInterval(function(){z.step();},13);
}
</script>
<style type="text/css">
div.test
{
width:400px; margin:5px auto; border:1px solid #ccc;
}
div.test strong
{ font-size:16px; background:#fff; border-bottom:1px solid #aaa; margin:0; display:block; padding:5px 0; text-decoration:underline; color:#059B9A; cursor:pointer; } div.test p { height:400px; background:#f1f1f1; margin:0;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div class="test">
<a name="header_1" id="header_1"></a>
<strong onclick="javascript:scroller('header_4', 800);">header_1 --> header_4</strong><p></p>
</div>
<div class="test">
<a name="header_2" id="header_2"></a>
<strong onclick="javascript:scroller('header_5', 800);">header_2 --> header_5</strong><p></p>
</div>
<div class="test">
<a name="header_3" id="header_3"></a>
<strong onclick="javascript:scroller('header_6', 800);">header_3 --> header_6</strong><p></p>
</div>
<div class="test">
<a name="header_4" id="header_4"></a>
<strong onclick="javascript:scroller('header_7', 800);">header_4 --> header_7</strong><p></p>
</div>
<div class="test">
<a name="header_5" id="header_5"></a>
<strong onclick="javascript:scroller('header_3', 800);">header_5 --> header_3</strong><p></p>
</div>
<div class="test">
<a name="header_6" id="header_6"></a>
<strong onclick="javascript:scroller('header_2', 800);">header_6 --> header_2</strong><p></p>
</div>
<div class="test">
<a name="header_7" id="header_7"></a>
<strong onclick="javascript:scroller('header_1', 800);">header_7 --> header_1</strong><p></p>
</div>
</form>
</body>
</html>
