<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>jQuery</title>
<script src="jquery-3.3.1.min.js"></script>
</head>
<body>
<script type="text/javascript">
$(function(){
// 按钮单击时执行
$("#btnInfo1").click(function(){
$("#div1").hide("slow",function(){
alert("图层现在被隐藏了");
});
});
})
</script>
<div id="div1" style="width:60px;height:60px;background-color:red;"></div><br>
<button id="btnInfo1" type="button">callback</button>
</body>
</html>