js 锚点平滑定位

<html>
    <head>
        <style type="text/css">
            <!--
            div.test {
            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>
        <style type="text/css" mce_bogus="1">
            div.test {
                 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>
        <script type="text/javascript">
            
            function intval(v){
                v = parseInt(v);
                return isNaN(v) ? 0 : v;
            } // ?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
                };
            } // ?取??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
                };
            } // ?点(Anchor)?平滑跳?    
            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)
                };
                z.timer = window.setInterval(function(){
                    z.step();
                }, 13);
            }
        </script>
    </head>
    <body>
        <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>
    </body>
</html>
原文地址:https://www.cnblogs.com/zcy_soft/p/2161881.html