当页面滚动到距顶部一定高度时某DIV自动隐藏和显示、弹窗、垂直居中
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<meta name="viewport" content="width=device-width,initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no" />
<meta content="yes" name="apple-mobile-web-app-capable" />
<meta content="black" name="apple-mobile-web-app-status-bar-style" />
<meta content="telephone=no" name="format-detection" />
<style type="text/css">
*{ margin: 0; padding: 0; }
body{ max-width: 640px; margin: 0 auto; }
.div1{ background: #D5D4D4;height: 500px; margin-bottom: 10px; overflow: hidden; font-size: 50px; }
.div2{ background: #D5D4D4; height: 500px; margin-bottom: 10px; overflow: hidden; font-size: 50px;}
.div3{ background: #D5D4D4; height: 500px; margin-bottom: 10px; overflow: hidden; font-size: 50px;}
/*弹窗样式*/
.public_pay_popup{background-color: rgba(0,0,0,.6);position: fixed;width: 100%;height: 100%;top:0;left:0;z-index: 39;display: none;}
.public_pp_box{position: absolute;width: 80%;background-color: #fff;top:50%;left:50%;transform: translate(-50%, -50%);-webkit-transform: translate(-50%, -50%);padding:20px 10px 10px;box-sizing: border-box;text-align: center;color: #3a3a3a;font-size: 16px;border-radius: 6px}
.public_pp_price,.public_pp_tit{padding:10px 0 6px;}
.public_pp_price strong{color: #ce0000;font-size: 18px;}
.public_pp_close{position: absolute;right:0;top:0;width: 40px;height: 40px;font-weight: 700;font-size:20px;line-height: 40px;color: #666}
.public_pay_bottom{position: fixed;bottom: 0;left: 0;width: 100%;height: 40px;line-height: 40px;text-align: center;font-size: 18px;background-color: #3393ab;color: #fff;z-index: 1;display: none;}
</style>
</head>
<body>
<div class="div1 J_payBottomShow J_payPopupShow">1</div>
<div class="div2 J_payPopupShow">2</div>
<div class="div3 J_payPopupShow">3</div>
<!-- 弹窗 -->
<div class="public_pay_popup" id="publicPayPopup">
<div class="public_pp_box">
<div class="public_pp_close" id="publicPPClose">X</div>
<div class="public_pp_tit">解锁查看所有测算结果</div>
<div class="public_pp_price"><span>统一鉴定价：</span></div>
</div>
</div>
<!-- 按钮 -->
<div style=" height: 25px;"></div>
<div class="public_pay_bottom" id="publicPayBottom">付费解锁所有项</div>
<script src="http://apps.bdimg.com/libs/jquery/1.9.1/jquery.min.js"></script>
<script type="text/javascript">
//底部悬浮
;(function($){
$.fn.publicPopup=function(opt){
var pp=$('#publicPayPopup');
var ppClose=$('#publicPPClose');
var topShow=$(".J_payBottomShow").length>0?$(".J_payBottomShow").offset().top:200;
var ppShow=$(".J_payPopupShow").length>0?$(".J_payPopupShow"):'';
return this.each(function(){
var $this=$(this);
$(window).scroll(function(){
var wt=$(window).scrollTop();
wt>topShow?$this.fadeIn():$this.fadeOut();
});
$this.on('click',function(){
pp.show();
});
ppClose.on('click',function(){
pp.hide();
})
ppShow?ppShow.on('click',function(){pp.show()}):'';
});
};
})(jQuery);
$("#publicPayBottom").publicPopup();
</script>
</body>
</html>
效果如图：
弹窗：
