jQuery滚动页面当DIV到达顶部时固定在顶部，到底部是固定在底部 - 快车库

jQuery滚动页面当DIV到达顶部时固定在顶部，到底部是固定在底部
可以做类似美团网右侧的浏览记录效果
直接上代码：

<!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>

  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

  <title>jQuery滚动页面当DIV到达顶部时固定在顶部，到底部是固定在底部</title>

  </head>

  <style>

  body{margin:0; padding:0; background:#fff}

  div{width:100%;}

  </style>

  <script src="http://libs.baidu.com/jquery/1.9.0/jquery.js"></script>

  <body>

  <div style="height:100px;background:#999"></div>

  <div style="height:200px;">

  <div id="menu" style="background:green; height:200px;"></div>

  </div>

  <div style="height:200px;"></div>

  <div id="bottom" style="background:red; height:200px; margin-top:100px;"></div>

  <div style="height:800px;background:#999"></div>

  <script type="text/javascript">

  $(function () {

  var ie6 = document.all;

  var dv = $('#menu'), st, botv;

  var bv = $('#bottom');

  dv.attr('otop', dv.offset().top);

  dv.attr('oheight', dv.height());
  $(window).scroll(function () {

  st = Math.max(document.body.scrollTop || document.documentElement.scrollTop);

  botv=bv.offset().top-st-parseInt(dv.attr('oheight'));

  if (st > parseInt(dv.attr('otop'))) {

  if(parseInt(bv.offset().top-st)<parseInt(dv.attr('oheight'))){

  dv.css({ 'position': 'fixed', top: botv });

  }else{

  if (ie6) {//IE6不支持fixed属性，所以只能靠设置position为absolute和top实现此效果

  dv.css({ position: 'absolute', top: st });

  }

  else if (dv.css('position') != 'fixed') dv.css({ 'position': 'fixed', top: 0 });

  }

  } else if (dv.css('position') != 'static') dv.css({ 'position': 'static' });

  });

  });

  </script>

  </body>

  </html>