JQuery fixed floating sidebar implementation ideas and code

  • 2020-03-30 04:00:30
  • OfStack

Present application of this feature is very common, if the page is higher, when the scroll bar below the page and the sidebar will be a fixed following browser DIV box, now the idea is this: first of all need to follow for DIV distance at the top of the page, and then judge, when the browser scroll distance is greater than the distance is the distance between the top DIV itself, then add CSS properties can be fixed.

The following code

HTML code:


<div id="header">header</div>
<div id="sidebarWrap">
<div id="sidebar">Sidebar</div>
</div>
<div id="main">Main</div>
<div id="footer">footer</div>

The CSS code:


body {
margin: 10px auto;
font-family: sans-serif;
width: 500px;
}
div {
border-radius: 5px;
box-shadow: 1px 2px 5px rgba(0,0,0,0.3);
border: 1px solid #ccc;
padding: 5px;
}
#sidebarWrap {
height: 400px;
width: 210px;
float: right;
position: relative;
box-shadow: none;
border: none;
margin: 0;
padding: 0;
}
#main {
width: 270px;
height: 4000px;
}
#footer {
clear: both;
margin: 10px 0;
}
#sidebar {
width: 200px;
height: 300px;
position: absolute;
}
#header {
height: 200px;
margin-bottom: 10px;
}
#sidebar.fixed {
position: fixed;
top: 0;
}
#footer { height: 600px; }
#footer { height: 600px; }

JavaScript code:


$(function() {
var top = $('#sidebar').offset().top - parseFloat($('#sidebar').css('marginTop').replace(/auto/, 0));
var footTop = $('#footer').offset().top - parseFloat($('#footer').css('marginTop').replace(/auto/, 0));

var maxY = footTop - $('#sidebar').outerHeight();

$(window).scroll(function(evt) {
var y = $(this).scrollTop();
if (y > top) {
if (y < maxY) {
$('#sidebar').addClass('fixed').removeAttr('style');
} else {
$('#sidebar').removeClass('fixed').css({
position: 'absolute',
top: (maxY - top) + 'px'
});
}
} else {
$('#sidebar').removeClass('fixed');
}
});
});

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