js 固定悬浮效果实现思路代码

<script type="text/javascript"> 
(function($){ 
var ele_fix = $("#div_right"); //浮动窗口 
var _main = $(".main"); //浮动区域 
var ele_offset_top = ele_fix.offset().top; //浮动区域高度 
$(window).scroll(function(){ 
var scro_top = $(this).scrollTop(); //当前高度 
var fix_foot_pos = parseInt(ele_fix.height())+parseInt(scro_top)-10; //浮动框最底部到最顶部高度 
var mainpos = parseInt(_main.offset().top)+parseInt(_main.height()); 
if(scro_top <= ele_offset_top&&fix_foot_pos<mainpos){ 
ele_fix.css({position: "static", top: -10}); 
}else if(scro_top>ele_offset_top&&fix_foot_pos<mainpos){ 
ele_fix.css({position: "fixed", top: -10}); 
}else if(scro_top>ele_offset_top&&fix_foot_pos>mainpos){ 
var posi = mainpos-fix_foot_pos-10; 
ele_fix.css({position: "fixed", top: posi}); 
} 
}); 
/* 
//方案二 
$(window).bind("scroll",function() { 
var temp = '1165'; 
//判断往下滚 
if ($(document).scrollTop() > temp) { //如果大于这个高度，就置顶 
flag = false; 
$('#div_right').css({'position':'fixed', 'top':'-10px', 'margin-top':'0px'}); 
} 
if ($(document).scrollTop() <= temp) { //如果小于这个高度，则恢复原来状态 
flag = true; 
$('#div_right').css('position',''); 
} 
}); 

*/ 
})(jQuery); 
</script>