固定背景实现的背景滚动特效示例分享
分享一个来自corpse的固定背景滚动特效，使用background-attachment: fixed和导航菜单，页面会非常平滑的滚动。
HTML
<div id="cbp-fbscroller" class="cbp-fbscroller">
<nav>
<a href="#fbsection1" class="cbp-fbcurrent">Section 1</a>
<a href="#fbsection2">Section 2</a>
<a href="#fbsection3">Section 3</a>
<a href="#fbsection4">Section 4</a>
<a href="#fbsection5">Section 5</a>
</nav>
<section id="fbsection1"></section>
<section id="fbsection2"></section>
<section id="fbsection3"></section>
<section id="fbsection4"></section>
<section id="fbsection5"></section>
</div>
CSS
/* Set all parents to full height */
html, body,
.container,
.cbp-fbscroller,
.cbp-fbscroller section {
height: 100%;
}
/* The nav is fixed on the right side and we center it by translating it 50%
(we don't know it's height so we can't use the negative margin trick) */
.cbp-fbscroller > nav {
position: fixed;
z-index: 9999;
right: 100px;
top: 50%;
-webkit-transform: translateY(-50%);
-moz-transform: translateY(-50%);
-ms-transform: translateY(-50%);
transform: translateY(-50%);
}
.cbp-fbscroller > nav a {
display: block;
position: relative;
color: transparent;
height: 50px;
}
.cbp-fbscroller > nav a:after {
content: '';
position: absolute;
width: 24px;
height: 24px;
border-radius: 50%;
border: 4px solid #fff;
}
.cbp-fbscroller > nav a:hover:after {
background: rgba(255,255,255,0.6);
}
.cbp-fbscroller > nav a.cbp-fbcurrent:after {
background: #fff;
}
/* background-attachment does the trick */
.cbp-fbscroller section {
position: relative;
background-position: top center;
background-repeat: no-repeat;
background-size: cover;
background-attachment: fixed;
}
#fbsection1 {
background-image: url(../images/1.jpg);
}
#fbsection2 {
background-image: url(../images/2.jpg);
}
#fbsection3 {
background-image: url(../images/3.jpg);
}
#fbsection4 {
background-image: url(../images/4.jpg);
}
#fbsection5 {
background-image: url(../images/5.jpg);
}
Javascript
/**
* cbpFixedScrollLayout.js v1.0.0
* http://www.codrops.com
*
* Licensed under the MIT license.
* http://www.opensource.org/licenses/mit-license.php
*
* Copyright 2013, Codrops
* http://www.codrops.com
*/
var cbpFixedScrollLayout = (function() {
// cache and initialize some values
var config = {
// the cbp-fbscroller′s sections
$sections : $( '#cbp-fbscroller > section' ),
// the navigation links
$navlinks : $( '#cbp-fbscroller > nav:first > a' ),
// index of current link / section
currentLink : 0,
// the body element
$body : $( 'html, body' ),
// the body animation speed
animspeed : 650,
// the body animation easing (jquery easing)
animeasing : 'easeInOutExpo'
};
function init() {
// click on a navigation link: the body is scrolled to the position of the respective section
config.$navlinks.on( 'click', function() {
scrollAnim( config.$sections.eq( $( this ).index() ).offset().top );
return false;
} );
// 2 waypoints defined:
// First one when we scroll down: the current navigation link gets updated.
// A `new section′ is reached when it occupies more than 70% of the viewport
// Second one when we scroll up: the current navigation link gets updated.
// A `new section′ is reached when it occupies more than 70% of the viewport
config.$sections.waypoint( function( direction ) {
if( direction === 'down' ) { changeNav( $( this ) ); }
}, { offset: '30%' } ).waypoint( function( direction ) {
if( direction === 'up' ) { changeNav( $( this ) ); }
}, { offset: '-30%' } );
// on window resize: the body is scrolled to the position of the current section
$( window ).on( 'debouncedresize', function() {
scrollAnim( config.$sections.eq( config.currentLink ).offset().top );
} );
}
// update the current navigation link
function changeNav( $section ) {
config.$navlinks.eq( config.currentLink ).removeClass( 'cbp-fbcurrent' );
config.currentLink = $section.index( 'section' );
config.$navlinks.eq( config.currentLink ).addClass( 'cbp-fbcurrent' );
}
// function to scroll / animate the body
function scrollAnim( top ) {
config.$body.stop().animate( { scrollTop : top }, config.animspeed, config.animeasing );
}
return { init : init };
})();