我想创建一个div,它位于一个内容块的下面,但一旦页面已经滚动到足以接触其顶部边界,就会固定在原地并与页面滚动。
当前回答
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。
其他回答
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
这里是如何不使用jquery(更新:看到其他答案,你现在可以只使用CSS)
var startProductBarPos=-1; window.onscroll=function(){ var bar = document.getElementById('nav'); if(startProductBarPos<0)startProductBarPos=findPosY(bar); if(pageYOffset>startProductBarPos){ bar.style.position='fixed'; bar.style.top=0; }else{ bar.style.position='relative'; } }; function findPosY(obj) { var curtop = 0; if (typeof (obj.offsetParent) != 'undefined' && obj.offsetParent) { while (obj.offsetParent) { curtop += obj.offsetTop; obj = obj.offsetParent; } curtop += obj.offsetTop; } else if (obj.y) curtop += obj.y; return curtop; } * {margin:0;padding:0;} .nav { border: 1px red dashed; background: #00ffff; text-align:center; padding: 21px 0; margin: 0 auto; z-index:10; width:100%; left:0; right:0; } .header { text-align:center; padding: 65px 0; border: 1px red dashed; } .content { padding: 500px 0; text-align:center; border: 1px red dashed; } .footer { padding: 100px 0; text-align:center; background: #777; border: 1px red dashed; } <header class="header">This is a Header</header> <div id="nav" class="nav">Main Navigation</div> <div class="content">Hello World!</div> <footer class="footer">This is a Footer</footer>
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");
});
});
截至2017年1月和Chrome 56的发布,大多数常用的浏览器都支持CSS中的position: sticky属性。
#thing_to_stick {
position: sticky;
top: 0px;
}
在火狐和Chrome浏览器中都是如此。
在Safari中,你仍然需要使用position: -webkit-sticky。
Polyfills可用于Internet Explorer和Edge;https://github.com/wilddeer/stickyfill似乎是个不错的网站。
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。