<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
$("button").click(function(){
$.ajax({url: "demo_test.txt", async: true,success: function(result){
$("#div1").html(result);
}});
});
});
</script>
</head>
<body>
<div id="div1"><h2>Let jQuery AJAX Change This Text</h2></div>
<button>Get External Content</button>
</body>
</html>
当我单击按钮时，AJAX调用什么也没有显示，而且我确定控制台没有错误，请帮帮我！
