当将要显示模态时，会引发Bootstrap中的show.bs.modal事件。
此处，警报是使用同一事件设置的，并且当准备显示模型时，将触发该事件。这导致将警报分发给访客。
这样，我还设置了一个按钮，单击该模态以打开，如下面的代码片段所示-
$(document).ready(function(){
$("#button1").click(function(){
$("#newModal").modal("show");
});
$("#newModal").on('show.bs.modal', function () {
alert('The modal will be displayed now!');
});
});以下是在Bootstrap中实现show.bs.modal事件的示例-
<!DOCTYPE html>
<html>
<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/3.3.7/css/bootstrap.min.css">
<script src="https://cdn.staticfile.org/jquery/3.3.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>
<body>
<div class="container">
<h2>Entrance Exams</h2>
<p>The following is the result of the entrance exam:</p>
<button type="button" class="btn btn-default btn-lg" id="button1">Result</button>
<div class="modal fade" id="newModal" role="dialog">
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal">×</button>
<h4 class="modal-title">Selected Students</h4>
</div>
<div class="modal-body">
<p>Harry and Chris cleared the entrance exam.</p>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-primary" data-dismiss="modal">Close</button>
</div>
</div>
</div>
</div>
</div>
<script>
$(document).ready(function(){
$("#button1").click(function(){
$("#newModal").modal("show");
});
$("#newModal").on('show.bs.modal', function () {
alert('The modal will be displayed now!');
});
});
</script>
</body>
</html>