您好，我目前在视差网站上工作。我想添加一个在用户滚动时向下移动的图像......但仅限于网站的某个部分。所以4个部分向下......图像在那里......它随着用户向下滚动而移动......然后消失在第5个部分后面，我们不再看到它。
我试图对此网站产生类似的效果：Website
当你向下滚动时......你会看到＆＃34;关于＆＃34;在div之间移动。我想实现这一目标。
当我这样做时......它出现在第一部分的顶部，并一直停留在屏幕上。
这是一个JSfiddle示例。它只显示网站的一部分：fiddle
我知道它与定位有关。但我希望它留在DIV中，而不是放在整个页面内。
// Create cross browser requestAnimationFrame method:
window.requestAnimationFrame = window.requestAnimationFrame
|| window.mozRequestAnimationFrame
|| window.webkitRequestAnimationFrame
|| window.msRequestAnimationFrame
|| function(f){setTimeout(f, 1000/60)}
var bubble1 = document.getElementById('bubbles1')
var bubble2 = document.getElementById('bubbles2')
var fish = document.getElementById('fish')
var scrollheight = document.body.scrollHeight // height of entire document
var windowheight = window.innerHeight // height of browser window
function parallaxbubbles(){
var scrolltop = window.pageYOffset // get number of pixels document has scrolled vertically
var scrollamount = (scrolltop / (scrollheight-windowheight)) * 100 // get amount scrolled (in %)
bubble1.style.top = scrolltop * .2 + 'px' // move bubble1 at 20% of scroll speed
bubble2.style.top = -scrolltop * .5 + 'px' // move bubble2 at 50% of scroll speed
fish.style.left = -100 + scrollamount + '%'
}
window.addEventListener('scroll', function(){ // on page scroll
requestAnimationFrame(parallaxbubbles) // call parallaxbubbles() on next available screen repaint
}, false)
window.addEventListener('resize', function(){ // on window resize
var scrollamount = (scrolltop / (scrollheight-windowheight)) * 100 // get amount scrolled (in %)
fish.style.left = -100 + scrollamount + '%'
}, false).cd-main-content {
/* I need to assign a min-height to the main content so that the children can inherit it*/
height: 60%;
position: relative;
/*z-index: 1;*/
}
.cd-fixed-bg {
position: relative;
min-height: 100%;
background-size: cover;
background-repeat: no-repeat;
background-position: center center;
z-index: 1;
}
.cd-fixed-bg h1, .cd-fixed-bg h2 {
position: absolute;
left: 50%;
top: 50%;
bottom: auto;
right: auto;
-webkit-transform: translateX(-50%) translateY(-50%);
-moz-transform: translateX(-50%) translateY(-50%);
-ms-transform: translateX(-50%) translateY(-50%);
-o-transform: translateX(-50%) translateY(-50%);
transform: translateX(-50%) translateY(-50%);
width: 90%;
max-width: 1170px;
text-align: center;
font-size: 30px;
font-size: 1.875rem;
text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
color: white;
}
.cd-fixed-bg.cd-bg-1 {
background-image: url("../images/content/grey.png");
}
.cd-fixed-bg.cd-bg-2 {
background-image: url("../images/content/cd-background-2.jpg");
}
@media only screen and (min-width: 768px) {
.cd-fixed-bg h1, .cd-fixed-bg h2 {
font-size: 36px;
}
}
@media only screen and (min-width: 1170px) {
.cd-fixed-bg {
background-attachment: fixed;
}
.cd-fixed-bg h1, .cd-fixed-bg h2 {
font-size: 48px;
font-weight: 300;
}
}
.cd-scrolling-bg {
position: relative;
min-height: 50%;
padding: 4em 0;
line-height: 1.6;
box-shadow: 0 0 50px rgba(0, 0, 0, 0.5);
z-index: 2;
}
/*.cd-scrolling-bg.cd-color-1 {
background-color: #ffffff;
color: #000000;
}*/
.cd-scrolling-bg.cd-color-2 {
background-color: #1c1c1c;
background: rgba(48,48,48,1);
background: -moz-radial-gradient(center, ellipse cover, rgba(48,48,48,1) 0%, rgba(56,56,56,1) 0%, rgba(28,28,28,1) 46%, rgba(10,10,10,1) 100%);
background: -webkit-gradient(radial, center center, 0px, center center, 100%, color-stop(0%, rgba(48,48,48,1)), color-stop(0%, rgba(56,56,56,1)), color-stop(46%, rgba(28,28,28,1)), color-stop(100%, rgba(10,10,10,1)));
background: -webkit-radial-gradient(center, ellipse cover, rgba(48,48,48,1) 0%, rgba(56,56,56,1) 0%, rgba(28,28,28,1) 46%, rgba(10,10,10,1) 100%);
background: -o-radial-gradient(center, ellipse cover, rgba(48,48,48,1) 0%, rgba(56,56,56,1) 0%, rgba(28,28,28,1) 46%, rgba(10,10,10,1) 100%);
background: -ms-radial-gradient(center, ellipse cover, rgba(48,48,48,1) 0%, rgba(56,56,56,1) 0%, rgba(28,28,28,1) 46%, rgba(10,10,10,1) 100%);
background: radial-gradient(ellipse at center, rgba(48,48,48,1) 0%, rgba(56,56,56,1) 0%, rgba(28,28,28,1) 46%, rgba(10,10,10,1) 100%);
filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#303030', endColorstr='#0a0a0a', GradientType=1 );
}
.cd-scrolling-bg.cd-color-3 {
background-color: #00161B;
color: #3d3536;
}
@media only screen and (min-width: 768px) {
.cd-scrolling-bg {
padding: 8em 0;
font-size: 20px;
font-size: 1.25rem;
line-height: 2;
font-weight: 300;
}
}
#bubbles1{
width: 100%;
height: 100%;
bottom: 0;
left: 0;
position: absolute;
z-index: -1;
background: url(http://www.i2clipart.com/cliparts/9/2/6/b/clipart-bubble-926b.png) 5% 80% no-repeat;
}
/*
#bubbles2{
background: url(bubbles3.png) 95% 90% no-repeat;
}*/<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<main class="cd-main-content parallax">
<div class="cd-scrolling-bg cd-color-2 parallax">
<div class="cd-container">
<p>
Lorem ipsum dolor sit amet, consectetur adipisicing elit. Dolore incidunt suscipit similique, dolor corrupti cumque qui consectetur autem laborum fuga quas ipsam doloribus sequi, mollitia, repellendus sapiente repudiandae labore rerum amet culpa inventore, modi non. Quo nisi veritatis vitae nam, labore fugit. Inventore culpa iusto, officia exercitationem. Voluptates quibusdam odit odio incidunt consequatur, consectetur aspernatur optio vitae molestias, quas repellendus fugit ullam culpa, eligendi et dignissimos voluptatibus illum? Molestias aliquam nostrum quasi ipsa culpa, iusto explicabo ut error, consequuntur enim temporibus, adipisci tempora voluptate, id consequatur mollitia eveniet blanditiis. Illo quod repellendus alias? Cum rem doloremque adipisci accusantium? Saepe, necessitatibus!
</p>
</div> <!-- cd-container -->
</div> <!-- cd-scrolling-bg -->
<div class="cd-scrolling-bg cd-color-3">
<div id="bubbles1"></div>
<h2>Lorem ipsum dolor sit amet.</h2>
</div> <!-- cd-fixed-bg -->
<div class="cd-scrolling-bg cd-color-3">
<div class="container">
<!--this is the bubble image-->
<div class="row-fluid">
<div class="span3">
<div class="text-widget widget">
<h4>About Me</h4>
<p>Lorem ipsum dolor nonus amet, consectetur ex adipisicing elit, sed do eiusmod incididunt ut labore et
dolore magna aliqua. Ut enim ad ex minim veniam, quis nostrud lorem exercitation ullamco laboris
nisi ut aliquip nesciunt aliqua.</p>
</div>
</div>
<div class="span3">
</div>
<div class="span3">
</div>
<div class="span3">
</div>
</div>
</div>
</div>
答案 0 :(得分：2)
首先，我们必须计算每个部分的相对滚动位置。我们通过计算窗口底部距离顶部的距离来做到这一点。当部分出现在窗口底部时它从0开始，当部分顶部移动（WINDOW_HEIGHT + SECTION_HEIGHT）像素时结束于1。此时，窗口中不再显示该部分。
就是这样。然后我们使用相对滚动位置部分通过设置它们的css顶部位置来移动气泡。
我们可以更多地玩它并介绍允许我们在气泡出现时设置的选项，并在部分相对滚动位置方面消失。因此，例如，我们希望当一个部分为0.5滚动时出现一个气泡，当该部分为0.8滚动时消失。我们通过操纵气泡必须行进的路径（和顶部偏移）的长度来做到这一点。
有关详细信息，请参阅此JsFiddle：http://jsfiddle.net/jkk7t7Lk/10/（注意：此示例使用jQuery）
function moveBubbles() {
var windowHeight = $(window).height();
var scrollTop = $(window).scrollTop();
var scrollBottom = scrollTop + windowHeight;
$('.section').each(function() {
var sectionHeight = $(this).outerHeight(true);
var sectionTop = $(this).position().top;
var sectionBottom = sectionTop + sectionHeight;
var in_window = (sectionTop >= scrollTop && sectionTop <= scrollBottom)
|| (sectionBottom >= scrollTop && sectionBottom <= scrollBottom)
|| (sectionTop <= scrollTop && sectionBottom >= scrollBottom);
if (in_window)
{
var pathHeight = sectionHeight + windowHeight;
var position = (scrollBottom - sectionTop) / pathHeight; // <0, 1>
$(this).find('.bubble').each(function() {
var bubbleHeight = $(this).outerHeight(true);
var start = parseFloat($(this).data('start'));
var speed = 1 / (parseFloat($(this).data('end')) - start);
var bubble_path = (sectionHeight + bubbleHeight) * speed;
var offset_top = start * bubble_path;
var top = bubble_path * position - bubbleHeight - offset_top;
$(this).css('top', top);
});
}
});
}
$(document).ready(moveBubbles);
$(window).resize(moveBubbles);
$(window).scroll(moveBubbles);
<div class="section">
<span class="bubble" style="left: 50px;" data-start="0.5" data-end="0.75"></span>
Section 1
</div>
<div class="section">
<span class="bubble" style="left: 30px;" data-start="0.3" data-end="0.6"></span>
<span class="bubble" style="left: 100px;" data-start="0.4" data-end="1"></span>
<span class="bubble" style="left: 200px;" data-start="0" data-end="1"></span>
<span class="bubble" style="left: 300px;" data-start="0.2" data-end="0.55"></span>
Section 2
</div>
<div class="section">
<span class="bubble" style="left: 50px;" data-start="0.7" data-end="0.71"></span>
Section 3
</div>
<div class="section">
Section 4
</div>
.section {
height: 100vh;
border: 1px solid red;
position: relative;
overflow: hidden;
}
.bubble {
background-image: url(http://www.i2clipart.com/cliparts/9/2/6/b/clipart-bubble-926b.png);
width: 128px;
height: 128px;
position: absolute;
display: block;
}