jQuery 返回顶部效果 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>返回顶部</title>
    <script src="scripts/jquery-1.7.1.min.js"></script>
</head>
<body>
<script type="text/javascript"> 
$(function(){
var toppos = 0;
$(".back_top_index").hide();
$(document).scroll(
  function(){
    toppos=$(document).scrollTop();
    var oClient =$(window).height();//当前窗口可视区域高度
    if(toppos>oClient){
      $(".back_top_index").fadeIn();  
    }else if(toppos==0){
      $(".back_top_index").fadeOut(); 
    }
  }
)
$(".back_top_index").click(function(){
    $("html,body").animate({scrollTop:0})
  })
   
})
</script> 
<div style="height:2000px;">3423424</div>
<div class="back_top_index">1</div>
<style>
.back_top_index{width: 50px;height: 50px;position: fixed;bottom: 10px;right: 10px;background-color: red;}
</style>
</body>
</html>

 

posted @ 2017-11-01 11:15  拈花醉  阅读(232)  评论(0)  编辑  收藏  举报