Javascript 确定元素是否已滚动到视图中
我试图确定当用户滚动时，视口中的元素是否可见。此代码在模态外部工作，但不在模态内部工作。我想这和Javascript 确定元素是否已滚动到视图中,javascript,angular,twitter-bootstrap,web,bootstrap-modal,Javascript,Angular,Twitter Bootstrap,Web,Bootstrap Modal,我试图确定当用户滚动时，视口中的元素是否可见。此代码在模态外部工作，但不在模态内部工作。我想这和 z-index，但无论我怎么尝试，它都不起作用。有什么想法吗 app.component.ts app.component.html <!DOCTYPE html> <html lang="en"> <head> <title>Bootstrap Example</title> <meta charset
z-index<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap Example</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<h2>Modal Example</h2>
<!-- Trigger the modal with a button -->
<button type="button" class="btn btn-info btn-lg" data-toggle="modal" data-target="#myModal">Open Modal</button>
<!-- Modal -->
<div class="modal fade" id="myModal" role="dialog">
<div class="modal-dialog">
<!-- Modal content-->
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal">×</button>
<h4 class="modal-title">Modal Header</h4>
</div>
<div class="modal-body">
<h1>Is div shown? {{isTestDivScrolledIntoView ? 'Yes!' : 'No :-('}}</h1>
<div #testDiv class="test">Test</div>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
</div>
</div>
</div>
</div>
</div>
</body>
</html>
检查名为“交点观察者”的功能。它允许您在元素进入视图时侦听它，然后触发回调
如果我的Modal系统出现z索引问题，这会有帮助吗？
p {
font-family: Lato;
}
h1 {
position: fixed;
top: 0;
padding-bottom: 5%;
}
.test {
text-align: center;
height: 40px;
margin-bottom: 40vh;
margin-top: 40vh;
border: 1px solid #000000;
}