Question

我尝试在用户滚动时尝试在黑白之间的渐变上更改页面的背景颜色。如果有意义，颜色将取决于用户当前在页面上滚动到哪里？这里有一些我已经有的代码但是它的唯一问题是，当用户没有在任何地方滚动网页不是黑色时。

＆＃13;

function scroll(){
	var body = document.body,
		  html = document.documentElement;
	var height = Math.max( body.scrollHeight, body.offsetHeight, html.clientHeight, html.scrollHeight, html.offsetHeight );
	var color = Math.round(((body.scrollTop + html.offsetHeight) / height) * 255);
	body.style.backgroundColor = "rgb("+color+","+color+","+color+")";
}

＆＃13;

html{
	height: 100%;
}
body{
	height: 200%;
	background: rgb(126,126,126);
}

＆＃13;

<!DOCTYPE html>
<html lang="en" dir="ltr">

  <body onscroll="scroll()">
    <script src="assets/JS/ScrollEffect.js"></script>
  </body>

</html>

＆＃13;

Answer 1

这样的东西？

＆＃13;

$(window).on('scroll', function(){
  var s = $(window).scrollTop(),
      d = $(document).height(),
      c = $(window).height();

  var scrolledArea = (s / (d - c));
  $("div").css("opacity", scrolledArea);
})

＆＃13;

body{
  margin: 0;
}

div{
  height: 500vh;
  background: #000;
  opacity: 0;
}

＆＃13;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>

</div>

＆＃13;

Answer 2

您必须使用html.scrollTop代替body.scrollTop。那是因为html元素变得可滚动了。 {200}高度的body元素溢出html，高度为100％，这是视口高度。

正文不会在这里滚动，所以你总是得到body.scrollTop = 0。但是html会滚动，所以你必须使用html.scrollTop。

元素body和html有时就像它们是一个元素一样。滚动行为就是这种情况。但有时他们表现得好像是两个独立的元素。这就是使用CSS设计样式的案例。

要从黑色变为白色（不是灰色到白色），您必须更改var height = html.scrollHeight - html.clientHeight;和var color = Math.round((html.scrollTop / height) * 255);

要使其在IE中运行，您需要添加： <html onscroll="scroll()">

如果可以，你应该使用jquery（就像Kushtrim建议的那样）。

function scroll(){
	var body = document.body,
		  html = document.documentElement;
	var height = html.scrollHeight - html.clientHeight;
	var color = Math.round((html.scrollTop / height) * 255);
	body.style.backgroundColor = "rgb("+color+","+color+","+color+")";
}

html{
	height: 100%;
}
body{
	height: 200%;
	background: rgb(0,0,0);
}

<!DOCTYPE html>
<html lang="en" dir="ltr" onscroll="scroll()">

  <body onscroll="scroll()">
    <script src="assets/JS/ScrollEffect.js"></script>
  </body>

</html>

Answer 3

试一试，阅读更多here

.container {
  width: 100%;
  min-width: 1200px;
  height: 100%;
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
}
.container .overlay {
  background: linear-gradient(to bottom, rgba(0, 160, 227, 0.5) 0%, rgba(176, 203, 31, 0.5) 50%, rgba(239, 127, 26, 0.5) 100%);
}
.container .slide {
  width: 100%;
  height: 600px;
  position: relative;
}

.secs {
  position: relative;
  height: 100%;
}
.secs .inside {
  width: 1200px;
  margin: 0 auto;
  height: 100%;
}
.secs.first {
  text-align: center;
}
.secs.first h1 {
  font-size: 60px;
  font-weight: bold;
  color: white;
  position: absolute;
  top: 50%;
  left: 50%;
  text-shadow: 1px 1px 1px #999,2px 2px 1px #999,3px 3px 1px #999,4px 4px 1px #999;
  transform: translate(-50%, -155%);
  z-index: 10;
}
.secs.first .inside {
  display: flex;
  justify-content: center;
  padding-top: 100px;
  position: relative;
}
.secs.first .bar {
  width: 80px;
  height: 350px;
  opacity: 0.54;
  box-shadow: 0px 0px 50px #fff;
  display: inline-block;
  margin-right: 25px;
  background: #fff;
}
.secs.first .bar:nth-child(1) {
  background: #00a0e3;
  animation: bars 5s infinite;
}
.secs.first .bar:nth-child(2) {
  transform: translateY(130px);
  background: #00a0e3;
  animation: bars1 5s infinite;
}
.secs.first .bar:nth-child(3) {
  transform: translateY(30px);
  background: #b0cb1f;
  animation: bars2 5s infinite;
}
.secs.first .bar:nth-child(4) {
  transform: translateY(80px);
  background: #b0cb1f;
  animation: bars3 5s infinite;
}
.secs.first .bar:nth-child(5) {
  transform: translateY(-30px);
  background: #ef7f1a;
  animation: bars4 5s infinite;
}
.secs.first .bar:nth-child(6) {
  transform: translateY(135px);
  background: #ef7f1a;
  animation: bars5 5s infinite;
}
.secs.first .bar:nth-child(7) {
  transform: translateY(55px);
  background: #e31e24;
  animation: bars6 5s infinite;
}
.secs.first .bar:nth-child(8) {
  background: #e31e24;
  animation: bars7 5s infinite;
}

@keyframes bars {
  0% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(130px);
  }
  100% {
    transform: translateY(0px);
  }
}
@keyframes bars1 {
  0% {
    transform: translateY(130px);
  }
  50% {
    transform: translateY(10px);
  }
  100% {
    transform: translateY(130px);
  }
}
@keyframes bars2 {
  0% {
    transform: translateY(30px);
  }
  50% {
    transform: translateY(0px);
  }
  100% {
    transform: translateY(30px);
  }
}
@keyframes bars3 {
  0% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(80px);
  }
  100% {
    transform: translateY(0px);
  }
}
@keyframes bars4 {
  0% {
    transform: translateY(-30px);
  }
  50% {
    transform: translateY(0px);
  }
  100% {
    transform: translateY(-30px);
  }
}
@keyframes bars5 {
  0% {
    transform: translateY(135px);
  }
  50% {
    transform: translateY(10px);
  }
  100% {
    transform: translateY(135px);
  }
}
@keyframes bars6 {
  0% {
    transform: translateY(55px);
  }
  50% {
    transform: translateY(0px);
  }
  100% {
    transform: translateY(55px);
  }
}
@keyframes bars7 {
  0% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(120px);
  }
  100% {
    transform: translateY(0px);
  }
}

<div class='container'>
  <div class='overlay'>
    <div class='slide secs first'></div>
    <div class='slide'></div>
    <div class='slide'></div>
    <div class='slide'></div>
    <div class='slide'></div>
    <div class='slide'></div>
    <div class='slide'></div>
  </div>
</div>

用户滚动时沿着渐变更改背景颜色

3 个答案: