标签：offset ons doc type ack 3.2 var back eee
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>获取当前视口元素</title>
<script src="script/jquery-3.2.1.min.js"></script>
</head>
<style>
div{
width: 800px;
height: 200px;
margin: 10px;
background-color: #eee;
}
</style>
<script>
(function($) {
$.expr[":"]["onScreen"] = function(elem) {
//可视上边和下边到页头距离
var viewTop = $(window).scrollTop();
var viewHeight = $(window).height();
var viewButtom = viewTop + viewHeight;
//元素上边和下边到页头距离
var elemTop = $(elem).offset().top;
var elemHeight = $(elem).height();
var elemButtom = elemTop + elemHeight;
//元素上边或下边可见
return (elemTop > viewTop && elemTop < viewButtom) || (elemButtom > viewTop && elemButtom < viewButtom);
//元素单个整体可见
return (elemTop > viewTop && elemTop < viewButtom) && (elemButtom > viewTop && elemButtom < viewButtom);
}
})($)
</script>
<body>
<div><h1>1</h1></div>
<div><h1>2</h1></div>
<div><h1>3</h1></div>
<div><h1>4</h1></div>
<div><h1>5</h1></div>
<div><h1>6</h1></div>
<div><h1>7</h1></div>
<div><h1>8</h1></div>
</body>
<script>
$(window).click(function() {
$("div").css("background-color","#eee");
$("div").filter(":onScreen").css("background-color","#aaa");
console.log($("div").filter(":onScreen"));
});
</script>
</html>
标签：offset ons doc type ack 3.2 var back eee
原文地址：http://www.cnblogs.com/huangtonghui/p/7229081.html
