我想在某个滚动位置更改图像。例如：
滚动100px show img1.jpg
Scroll 200px show img2.jpg
滚动300px show img3.jpg
Here我找到了一个例子。
有什么想法吗？
答案 0 :(得分：7)
您可以使用onScroll事件来收听滚动，检查滚动条的位置并更改图像或您想要的任何内容。您可以阅读有关onScroll事件here的更多信息。基本代码将是这样的：
var onScrollHandler = function() {
var newImageUrl = yourImageElement.src;
var scrollTop = document.documentElement.scrollTop || document.body.scrollTop;
if (scrollTop > 100) {
newImageUrl = "img1.jpg"
}
if (scrollTop > 200) {
newImageUrl = "img2.jpg"
}
if (scrollTop > 300) {
newImageUrl = "img3.jpg"
}
yourImageElement.src = newImageUrl;
};
object.addEventListener ("scroll", onScrollHandler);
当然yourImageElement应该替换为您想要更改的图像元素。
如果你有jQuery可用，你可以使用.scroll()方法而不是事件监听器和.scrollTop()来获取滚动条位置。
此外，您可能希望查看一些滚动/阅读库，例如skrollr。
答案 1 :(得分：1)
所以我只是回答这个旧线程，因为我试图在我的网站上实现相同的东西，但我发现实现它有点困难，所以我做了我自己的功能，它更容易实现和理解但有点儿错误，例如：如果用户使用滚动条而不是鼠标的滚轮，图像将不会改变，希望它可以帮助你：
<html>
<head>
<script>
function f() {
t1.src = "https://igu3ss.files.wordpress.com/2012/09/chess_king_4.jpg"
t1.height = "319"
t1.width = "330"
}
function f2() {
t1.src = "https://upload.wikimedia.org/wikipedia/commons/thumb/d/d3/Chess_piece_-_Black_queen.JPG/130px-Chess_piece_-_Black_queen.JPG"
t1.height = "319"
t1.width = "330"
}
function f3() {
t1.src = "https://asmoodle.asmadrid.org/blog/s16240/wp-content/uploads/sites/56/2014/12/protourney_knight_black_400.jpg"
t1.height = "244"
t1.width = "330"
}
function f4() {
t1.src = "https://thumbs.dreamstime.com/x/chess-knight-white-background-29811348.jpg"
t1.height = "244"
t1.width = "350"
}
function f5() {
t1.src = "http://cdn.craftsy.com/upload/3703789/pattern/115774/full_7439_115774_ChessKnightMachineEmbroideryDesign_1.jpg"
t1.height = "319"
t1.width = "350"
}
</script>
</head>
<body>
<div align="center" style="position: fixed; z-index: 20; left:38.5%; top:200">
<img src="no.png" height="319" width="330" name="t1">
</div>
</div>
<div class="container" onmouseover="f3()" style="padding:0; margin:0; width:100%;">
<img src="https://pixabay.com/static/uploads/photo/2016/01/11/22/05/background-1134468_960_720.jpg" width="100%">
</div>
<br>
<br>
<div class="container" onmouseover="f4()" style="padding:0; margin:0; width:100%;">
<img src="https://image.freepik.com/free-photo/lens-flare-abstract-backgound_21276999.jpg" width="100%">
</div>
<br>
<br>
<div class="container" onmouseover="f5()" style="padding:0; margin:0; width:100%;">
<img src="https://image.freepik.com/free-photo/lens-flare-abstract-backgound_21276999.jpg" width="100%">
</div>
<br>
<br>
<div class="container" onmouseover="f()" style="padding:0; margin:0; width:100%;"></div>
</body></html>
答案 2 :(得分：0)
$(window).on("scroll touchmove", function()
{
if ($(document).scrollTop() >= $("#one").position().top && $(document).scrollTop() < $("#two").position().top )
{
$('body').css('background-image', 'url(https://4.bp.blogspot.com/-Ivk46EkgQfk/WWjbo4TdJbI/AAAAAAAAFUo/gUD7JABklsIA1gWIr5LS1slyY4QuTMkEwCLcBGAs/s1600/gambar%2Bwallpaper%2Bmobil.jpg)')
};
if ($(document).scrollTop() >= $("#two").position().top && $(document).scrollTop() < $("#three").position().top)
{
$('body').css('background-image', 'url(https://i1.wp.com/cdn.catawiki.net/assets/marketing/uploads-files/45485-8bdcc8479f93d5a247ab844321b8b9d5e53c49a9-story_inline_image.jpg)')
};
if ($(document).scrollTop() >= $("#three").position().top && $(document).scrollTop() < $("#four").position().top )
{
$('body').css('background-image', 'url(https://s-media-cache-ak0.pinimg.com/originals/e1/7a/03/e17a0385726db90de1854177d4af2b4f.jpg)')
};
if ($(document).scrollTop() >= $("#four").position().top)
{
$('body').css('background-image', 'url(https://www.wallpaperup.com/uploads/wallpapers/2015/02/13/621414/6fc33c3ae65a58f9bb137f5cf011aebc.jpg)')
};
});*{
margin:0;
padding:0;
}
.main{
width:100%;
height:100vh;
background-image:url('https://4.bp.blogspot.com/-Ivk46EkgQfk/WWjbo4TdJbI/AAAAAAAAFUo/gUD7JABklsIA1gWIr5LS1slyY4QuTMkEwCLcBGAs/s1600/gambar%2Bwallpaper%2Bmobil.jpg');
background-size:100% 100%;
background-attachment:fixed;
transition: 1000ms;
}
section{
width: 100%;
min-height: 1px;
}
.content{
width:50%;
min-height:1px;margin-top:10%;
margin-left:10%;
color:white;
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body class='main'>
<section id="one">
<div class='content'>
<h1 style='font-size:5vw;'>first heading</h1>
<p style='font-size:3vw;' >description</p>
</div>
</section>
<section id="two" style='margin-top:100vh'>
<div class='content'>
<h1 style='font-size:5vw;'>second heading</h1>
<p style='font-size:3vw;'>description</p>
</div>
</section>
<section id="three" style='margin-top:100vh' >
<div class='content'>
<h1 style='font-size:5vw;'>third heading</h1>
<p style='font-size:3vw;'>description</p>
</div>
</section>
<section id="four" style='margin-top:100vh' >
<div class='content' style='margin-bottom:10%;'>
<h1 style='font-size:5vw;'>fourth heading</h1>
<p style='font-size:3vw;'>description</p>
</div>
</section>
</body>
</html>
文档
create a web folder first.
create a img sub folder // place all images into this folder
now create three files // in web folder
index.html
css.css
js.js
copy code given bellow and paste it.
save the program.
finally run the program
点击此链接以观看视频：https://www.youtube.com/watch?v=V97wCVY_SrQ
访问我们的网站以获取完整文档：https://nozzons.blogspot.com/
index.html
<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link href='css.css' rel='stylesheet' type='text/css'/>
<script src='js.js'></script>
</head>
<body class='main'>
<section id="one">
<div class='content'>
<h1 style='font-size:5vw;'>first heading</h1>
<p style='font-size:3vw;' >description</p>
</div>
</section>
<section id="two" style='margin-top:100vh'>
<div class='content'>
<h1 style='font-size:5vw;'>second heading</h1>
<p style='font-size:3vw;'>description</p>
</div>
</section>
<section id="three" style='margin-top:100vh' >
<div class='content'>
<h1 style='font-size:5vw;'>third heading</h1>
<p style='font-size:3vw;'>description</p>
</div>
</section>
<section id="four" style='margin-top:100vh' >
<div class='content' style='margin-bottom:10%;'>
<h1 style='font-size:5vw;'>fourth heading</h1>
<p style='font-size:3vw;'>description</p>
</div>
</section>
</body>
</html>
css.css
*{
margin:0;
padding:0;
}
.main{
width:100%;
height:100vh;
background-image:url('img/img_one.jpg');
background-size:100% 100%;
background-attachment:fixed;
transition: 1000ms;
}
section{
width: 100%;
min-height: 1px;
}
.content{
width:50%;
min-height:1px;margin-top:10%;
margin-left:10%;
color:white;
}
js.js
$(window).on("scroll touchmove", function()
{
if ($(document).scrollTop() >= $("#one").position().top && $(document).scrollTop() < $("#two").position().top )
{
$('body').css('background-image', 'url(img/img_one.jpg)')
};
if ($(document).scrollTop() >= $("#two").position().top && $(document).scrollTop() < $("#three").position().top)
{
$('body').css('background-image', 'url(img/img_two.jpg)')
};
if ($(document).scrollTop() >= $("#three").position().top && $(document).scrollTop() < $("#four").position().top )
{
$('body').css('background-image', 'url(img/img_three.jpg)')
};
if ($(document).scrollTop() >= $("#four").position().top)
{
$('body').css('background-image', 'url(img/img_four.jpg)')
};
});