♫【JS】offsetParent

This property will return null on Webkit if the element is hidden (the style.display of this element or any ancestor is "none") or if the style.position of the element itself is set to "fixed".

This property will return null on Internet Explorer (9) if the style.position of the element itself is set to "fixed". (Having display:none does not affect this browser.)

<!doctype html>
<html>
<head>
    <meta charset="utf-8">
    <title></title>
</head>
<body>
    <style>
        *{margin:0;padding:0}
        div{width:50%;padding:20px;border:5px solid green}
        #box1{position:relative}
        #box4{position:absolute;display:none;border-color:red}
    </style>
    <div id="box1">
        <div id="box2">
            <div id="box3">
                <div id="box4"></div>
            </div>
        </div>
    </div>
    <script src="http://upcdn.b0.upaiyun.com/libs/jquery/jquery-2.0.3.min.js"></script>
    <script>
        var $box3 = $('#box3')
        var $box4 = $('#box4')
        $box4.css({visibility:'hidden',display:'block'})

        var $box = $box4.offsetParent()
        // or
        var $box = $(document.getElementById('box4').offsetParent)

        $box4.css({visibility:'',display:'none'})
        var offset1 = $box3.offset()
        var offset2 = $box.offset()
        $box4.css({
            top: offset1.top + $box4.outerHeight() - parseInt($box.css('border-top-width'), 10) - offset2.top,
            left: offset1.left - parseInt($box.css('border-left-width'), 10) - offset2.left,
            display: 'block'
        })
    </script>
</body>
</html>
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原文地址：https://www.cnblogs.com/jzm17173/p/3532457.html