欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  web前端

使用JQUERY实现可变透明度返回顶部效果

程序员文章站 2022-04-10 23:03:13
...
1、在页面(HTML)<body></body>里加上A标签(返回顶部超链接)
<a href="#0" class="cd-top">Top</a>

2、添加css样式(可以写在页面里,也可以写在单独的css样式表里)

.cd-top {
  display: inline-block;
  height: 40px;
  width: 40px;
  position: fixed;
  bottom: 40px;
  right: 10px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
  /* image replacement properties */
  overflow: hidden;
  text-indent: 100%;
  white-space: nowrap;
  background: rgba(232, 98, 86, 0.8) url(../images/cd-top-arrow.svg) no-repeat center 50%;
  visibility: hidden;
  opacity: 0;
  -webkit-transition: all 0.3s;
  -moz-transition: all 0.3s;
  transition: all 0.3s;
}
.cd-top.cd-is-visible {
  /* the button becomes visible */
  visibility: visible;
  opacity: 1;
}
.cd-top.cd-fade-out {
  /* 如果用户继续向下滚动,这个按钮的透明度会变得更低 */
  opacity: .5;
}
.no-touch .cd-top:hover {
  background-color: #e86256;
  opacity: 1;
}
@media only screen and (min-width: 768px) {
  .cd-top {
    right: 20px;
    bottom: 20px;
  }
}
@media only screen and (min-width: 1024px) {
  .cd-top {
    height: 60px;
    width: 60px;
    right: 30px;
    bottom: 30px;
  }
}

3、加入js代码(加入js前,一定要先引用jquery库,否则会失效)

<script type="text/javascript" src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
$(document).ready(function($){
	// browser window scroll (in pixels) after which the "back to top" link is shown
	var offset = 300,
		//browser window scroll (in pixels) after which the "back to top" link opacity is reduced
		offset_opacity = 1200,
		//duration of the top scrolling animation (in ms)
		scroll_top_duration = 700,
		//grab the "back to top" link
		$back_to_top = $('.cd-top');

	//hide or show the "back to top" link
	$(window).scroll(function(){
		( $(this).scrollTop() > offset ) ? $back_to_top.addClass('cd-is-visible') : $back_to_top.removeClass('cd-is-visible cd-fade-out');
		if( $(this).scrollTop() > offset_opacity ) { 
			$back_to_top.addClass('cd-fade-out');
		}
	});
	//www.sucaijiayuan.com
	//smooth scroll to top
	$back_to_top.on('click', function(event){
		event.preventDefault();
		$('body,html').animate({
			scrollTop: 0 ,
		 	}, scroll_top_duration
		);
	});

});

以上就是使用JQUERY实现可变透明度返回顶部效果的详细内容,更多请关注其它相关文章!