这就是我用jquery做的。这都是根据堆栈溢出的各种答案拼凑起来的。这个解决方案缓存选择器以获得更快的性能，并且还解决了当粘性div变得粘性时的“跳跃”问题。

在jsfiddle: http://jsfiddle.net/HQS8s/上查看它

CSS:

.stick {
    position: fixed;
    top: 0;
}

JS:

$(document).ready(function() {
    // Cache selectors for faster performance.
    var $window = $(window),
        $mainMenuBar = $('#mainMenuBar'),
        $mainMenuBarAnchor = $('#mainMenuBarAnchor');

    // Run this on scroll events.
    $window.scroll(function() {
        var window_top = $window.scrollTop();
        var div_top = $mainMenuBarAnchor.offset().top;
        if (window_top > div_top) {
            // Make the div sticky.
            $mainMenuBar.addClass('stick');
            $mainMenuBarAnchor.height($mainMenuBar.height());
        }
        else {
            // Unstick the div.
            $mainMenuBar.removeClass('stick');
            $mainMenuBarAnchor.height(0);
        }
    });
});

下面是一个使用jquery-visible插件的例子:http://jsfiddle.net/711p4em4/。

HTML:

<div class = "wrapper">
    <header>Header</header>
    <main>
        <nav>Stick to top</nav>
        Content
    </main>
    <footer>Footer</footer>
</div>

CSS:

* {
    margin: 0;
    padding: 0;
}

body {
    background-color: #e2e2e2;
}

.wrapper > header,
.wrapper > footer {
    font: 20px/2 Sans-Serif;
    text-align: center;
    background-color: #0040FF;
    color: #fff;
}

.wrapper > main {
    position: relative;
    height: 500px;
    background-color: #5e5e5e;
    font: 20px/500px Sans-Serif;
    color: #fff;
    text-align: center;
    padding-top: 40px;
}

.wrapper > main > nav {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    font: 20px/2 Sans-Serif;
    color: #fff;
    text-align: center;
    background-color: #FFBF00;
}

.wrapper > main > nav.fixed {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
}

JS(包括jquery-visible插件):

(function($){

    /**
     * Copyright 2012, Digital Fusion
     * Licensed under the MIT license.
     * http://teamdf.com/jquery-plugins/license/
     *
     * @author Sam Sehnert
     * @desc A small plugin that checks whether elements are within
     *       the user visible viewport of a web browser.
     *       only accounts for vertical position, not horizontal.
     */
    var $w = $(window);
    $.fn.visible = function(partial,hidden,direction){

        if (this.length < 1)
            return;

        var $t        = this.length > 1 ? this.eq(0) : this,
            t         = $t.get(0),
            vpWidth   = $w.width(),
            vpHeight  = $w.height(),
            direction = (direction) ? direction : 'both',
            clientSize = hidden === true ? t.offsetWidth * t.offsetHeight : true;

        if (typeof t.getBoundingClientRect === 'function'){

            // Use this native browser method, if available.
            var rec = t.getBoundingClientRect(),
                tViz = rec.top    >= 0 && rec.top    <  vpHeight,
                bViz = rec.bottom >  0 && rec.bottom <= vpHeight,
                lViz = rec.left   >= 0 && rec.left   <  vpWidth,
                rViz = rec.right  >  0 && rec.right  <= vpWidth,
                vVisible   = partial ? tViz || bViz : tViz && bViz,
                hVisible   = partial ? lViz || rViz : lViz && rViz;

            if(direction === 'both')
                return clientSize && vVisible && hVisible;
            else if(direction === 'vertical')
                return clientSize && vVisible;
            else if(direction === 'horizontal')
                return clientSize && hVisible;
        } else {

            var viewTop         = $w.scrollTop(),
                viewBottom      = viewTop + vpHeight,
                viewLeft        = $w.scrollLeft(),
                viewRight       = viewLeft + vpWidth,
                offset          = $t.offset(),
                _top            = offset.top,
                _bottom         = _top + $t.height(),
                _left           = offset.left,
                _right          = _left + $t.width(),
                compareTop      = partial === true ? _bottom : _top,
                compareBottom   = partial === true ? _top : _bottom,
                compareLeft     = partial === true ? _right : _left,
                compareRight    = partial === true ? _left : _right;

            if(direction === 'both')
                return !!clientSize && ((compareBottom <= viewBottom) && (compareTop >= viewTop)) && ((compareRight <= viewRight) && (compareLeft >= viewLeft));
            else if(direction === 'vertical')
                return !!clientSize && ((compareBottom <= viewBottom) && (compareTop >= viewTop));
            else if(direction === 'horizontal')
                return !!clientSize && ((compareRight <= viewRight) && (compareLeft >= viewLeft));
        }
    };

})(jQuery);

$(function() {
    $(window).scroll(function() {
        $(".wrapper > header").visible(true) ?
            $(".wrapper > main > nav").removeClass("fixed") :
            $(".wrapper > main > nav").addClass("fixed");
    });
});

这里还有一个版本供那些对其他版本有问题的人尝试。它结合了这个重复问题中讨论的技术，并动态生成所需的帮助器div，因此不需要额外的HTML。

CSS:

.sticky { position:fixed; top:0; }

JQuery:

function make_sticky(id) {
    var e = $(id);
    var w = $(window);
    $('<div/>').insertBefore(id);
    $('<div/>').hide().css('height',e.outerHeight()).insertAfter(id);
    var n = e.next();
    var p = e.prev();
    function sticky_relocate() {
      var window_top = w.scrollTop();
      var div_top = p.offset().top;
      if (window_top > div_top) {
        e.addClass('sticky');
        n.show();
      } else {
        e.removeClass('sticky');
        n.hide();
      }
    }
    w.scroll(sticky_relocate);
    sticky_relocate();
}

要使元素具有粘性，请执行以下操作:

make_sticky('#sticky-elem-id');

当元素变得粘滞时，代码管理剩余内容的位置，以防止它跳到粘滞元素留下的间隙中。当滚动到粘滞元素上方时，它还将粘滞元素返回到其原始的非粘滞位置。

你可以添加额外的3行，这样当用户滚动回顶部时，div将保持在原来的位置:

代码如下:

if ($(this).scrollTop() < 200 && $el.css('position') == 'fixed'){
    $('.fixedElement').css({'position': 'relative', 'top': '200px'});
}

您已经在谷歌Code的发行页面和Stack Overflow的编辑页面上看到过这个例子。

当你向上滚动时，CMS的答案不会恢复定位。以下是从Stack Overflow窃取的无耻代码:

function moveScroller() {
    var $anchor = $("#scroller-anchor");
    var $scroller = $('#scroller');

    var move = function() {
        var st = $(window).scrollTop();
        var ot = $anchor.offset().top;
        if(st > ot) {
            $scroller.css({
                position: "fixed",
                top: "0px"
            });
        } else {
            $scroller.css({
                position: "relative",
                top: ""
            });
        }
    };
    $(window).scroll(move);
    move();
}

<div id="sidebar" style="width:270px;"> 
  <div id="scroller-anchor"></div> 
  <div id="scroller" style="margin-top:10px; width:270px"> 
    Scroller Scroller Scroller
  </div>
</div>

<script type="text/javascript"> 
  $(function() {
    moveScroller();
  });
</script> 

还有一个简单的现场演示。

一个新兴的、无脚本的替代方案是position: sticky, Chrome、Firefox和Safari都支持它。请参阅HTML5Rocks和demo上的文章以及Mozilla文档。

我和你有同样的问题，最终制作了一个jQuery插件来解决它。它实际上解决了人们在这里列出的所有问题，而且还增加了一些可选特性。

选项

stickyPanelSettings = {
    // Use this to set the top margin of the detached panel.
    topPadding: 0,

    // This class is applied when the panel detaches.
    afterDetachCSSClass: "",

    // When set to true the space where the panel was is kept open.
    savePanelSpace: false,

    // Event fires when panel is detached
    // function(detachedPanel, panelSpacer){....}
    onDetached: null,

    // Event fires when panel is reattached
    // function(detachedPanel){....}
    onReAttached: null,

    // Set this using any valid jquery selector to 
    // set the parent of the sticky panel.
    // If set to null then the window object will be used.
    parentSelector: null
};

https://github.com/donnyv/sticky-panel

演示:http://htmlpreview.github.io/?https: / / github.com/donnyv/sticky-panel/blob/master/jquery.stickyPanel/Main.htm