jquery.nav.js定位导航滚动插件

jQuery.nav.js插件代码：

/*
 * jQuery One Page Nav Plugin
 * http://github.com/davist11/jQuery-One-Page-Nav
 *
 * Copyright (c) 2010 Trevor Davis (http://trevordavis.net)
 * Dual licensed under the MIT and GPL licenses.
 * Uses the same license as jQuery, see:
 * http://jquery.org/license
 *
 * @version 3.0.0
 *
 * Example usage:
 * $('#nav').onePageNav({
 *   currentClass: 'current',
 *   changeHash: false,
 *   scrollSpeed: 750
 * });
 */
;(function($, window, document, undefined){

    // our plugin constructor
    var OnePageNav = function(elem, options){
        this.elem = elem;
        this.$elem = $(elem);
        this.options = options;
        this.metadata = this.$elem.data('plugin-options');
        this.$win = $(window);
        this.sections = {};
        this.didScroll = false;
        this.$doc = $(document);
        this.docHeight = this.$doc.height();
    };

    // the plugin prototype
    OnePageNav.prototype = {
        defaults: {
            navItems: 'a',
            currentClass: 'current',
            changeHash: false,
            easing: 'swing',
            filter: '',
            scrollSpeed: 750,
            scrollThreshold: 0.5,
            begin: false,
            end: false,
            scrollChange: false
        },

        init: function() {
            // Introduce defaults that can be extended either
            // globally or using an object literal.
            this.config = $.extend({}, this.defaults, this.options, this.metadata);

            this.$nav = this.$elem.find(this.config.navItems);

            //Filter any links out of the nav
            if(this.config.filter !== '') {
                this.$nav = this.$nav.filter(this.config.filter);
            }

            //Handle clicks on the nav
            this.$nav.on('click.onePageNav', $.proxy(this.handleClick, this));

            //Get the section positions
            this.getPositions();

            //Handle scroll changes
            this.bindInterval();

            //Update the positions on resize too
            this.$win.on('resize.onePageNav', $.proxy(this.getPositions, this));

            return this;
        },

        adjustNav: function(self, $parent) {
            self.$elem.find('.' + self.config.currentClass).removeClass(self.config.currentClass);
            $parent.addClass(self.config.currentClass);
        },

        bindInterval: function() {
            var self = this;
            var docHeight;

            self.$win.on('scroll.onePageNav', function() {
                self.didScroll = true;
            });

            self.t = setInterval(function() {
                docHeight = self.$doc.height();

                //If it was scrolled
                if(self.didScroll) {
                    self.didScroll = false;
                    self.scrollChange();
                }

                //If the document height changes
                if(docHeight !== self.docHeight) {
                    self.docHeight = docHeight;
                    self.getPositions();
                }
            }, 250);
        },

        getHash: function($link) {
            return $link.attr('href').split('#')[1];
        },

        getPositions: function() {
            var self = this;
            var linkHref;
            var topPos;
            var $target;

            self.$nav.each(function() {
                linkHref = self.getHash($(this));
                $target = $('#' + linkHref);

                if($target.length) {
                    topPos = $target.offset().top;
                    self.sections[linkHref] = Math.round(topPos);
                }
            });
        },

        getSection: function(windowPos) {
            var returnValue = null;
            var windowHeight = Math.round(this.$win.height() * this.config.scrollThreshold);

            for(var section in this.sections) {
                if((this.sections[section] - windowHeight) < windowPos) {
                    returnValue = section;
                }
            }

            return returnValue;
        },

        handleClick: function(e) {
            var self = this;
            var $link = $(e.currentTarget);
            var $parent = $link.parent();
            var newLoc = '#' + self.getHash($link);

            if(!$parent.hasClass(self.config.currentClass)) {
                //Start callback
                if(self.config.begin) {
                    self.config.begin();
                }

                //Change the highlighted nav item
                self.adjustNav(self, $parent);

                //Removing the auto-adjust on scroll
                self.unbindInterval();

                //Scroll to the correct position
                self.scrollTo(newLoc, function() {
                    //Do we need to change the hash?
                    if(self.config.changeHash) {
                        window.location.hash = newLoc;
                    }

                    //Add the auto-adjust on scroll back in
                    self.bindInterval();

                    //End callback
                    if(self.config.end) {
                        self.config.end();
                    }
                });
            }

            e.preventDefault();
        },

        scrollChange: function() {
            var windowTop = this.$win.scrollTop();
            var position = this.getSection(windowTop);
            var $parent;

            //If the position is set
            if(position !== null) {
                $parent = this.$elem.find('a[href$="#' + position + '"]').parent();

                //If it's not already the current section
                if(!$parent.hasClass(this.config.currentClass)) {
                    //Change the highlighted nav item
                    this.adjustNav(this, $parent);

                    //If there is a scrollChange callback
                    if(this.config.scrollChange) {
                        this.config.scrollChange($parent);
                    }
                }
            }
        },

        scrollTo: function(target, callback) {
            var offset = $(target).offset().top;

            $('html, body').animate({
                scrollTop: offset
            }, this.config.scrollSpeed, this.config.easing, callback);
        },

        unbindInterval: function() {
            clearInterval(this.t);
            this.$win.unbind('scroll.onePageNav');
        }
    };

    OnePageNav.defaults = OnePageNav.prototype.defaults;

    $.fn.onePageNav = function(options) {
        return this.each(function() {
            new OnePageNav(this, options).init();
        });
    };

})( jQuery, window , document );
/* 代码整理：懒人之家 www.lanrenzhijia.com */

html代码：

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style type="text/css">
    * {
        margin: 0;
        padding: 0
    }

    li {
        list-style: none
    }
    a{text-decoration: none;}

    #nav {
        position: fixed;
        *left: 90px;
        top:100px;
    }

    #nav li {
        margin-bottom: 2px;
        width: 130px;
        height: 41px;
        line-height: 41px;
    }

    #nav a {
        background: #B18282;
        color: #fff;
        display: block;
        text-transform: uppercase;
        -ms-text-overflow: ellipsis;
        padding: 0 5px;
        text-overflow: ellipsis;
        overflow: hidden;
        white-space: nowrap;
    }

    #nav a:hover {
        background: #00d420;
        color: #fff;
    }

    #nav .current a {
        background: #00d420;
        color: #fff;
    }
    .head{margin: 0 auto; width: 100%; height: 100px; line-height: 100px; background: #D49B6D; text-align: center; font-size: 30px;}
    .main{ width: 800px; margin: 0 auto; }
    .box{ width: 600px; border:1px solid #ddd; margin-left: 140px; }
    </style>
</head>

<body>
    <div class="head">导航</div>
    <div class="main">
        <ul id="nav">
            <li><a href="#a0">花卉详情</a></li>
            <li><a href="#a1">介绍</a></li>
            <li><a href="#a2">形态特征</a></li>
            <li><a href="#a3">生长习性</a></li>
            <li><a href="#a4">栽培技术</a></li>
            <li><a href="#a5">主要价值</a></li>
        </ul>
        <div class="box">
            <div id="a0" style="height: 300px;border:1px solid #ddd;">花卉详情</div>
            <div id="a1" style="height: 300px;border:1px solid #ddd;">介绍</div>
            <div id="a2" style="height: 300px;border:1px solid #ddd;">形态特征</div>
            <div id="a3" style="height: 300px;border:1px solid #ddd;">生长习性</div>
            <div id="a4" style="height: 300px;border:1px solid #ddd;">栽培技术</div>
            <div id="a5" style="height: 300px;border:1px solid #ddd;">主要价值</div>
        </div>
    </div>
    <script src="http://apps.bdimg.com/libs/jquery/1.9.1/jquery.min.js"></script>
    <script src="js/jquery.nav.js"></script>
    <script>
    $(function() {
        $('#nav').onePageNav();
    });
    </script>
</body>

</html>

效果图：