User-1174608757 posted
Hi JagjitSingh,
According to your description ,I have made a sample here.I suggest you to use Jquery to accomplish your requirement.
You could loop the filename of items you selected in function .change() of Fileupload control.Here is the code,I hope it can help you.
Fileupload.aspx:
<head runat="server">
<title></title>
<script src="../Scripts/jquery-3.3.1.js"></script>
<script>
$(function () {
$('#FileUpload1').change(function () {
var fp = $("#FileUpload1");
var lg = fp[0].files.length;
var items = fp[0].files;
if (lg > 0)
{
for (var i = 0; i < lg; i++) {
var fileName = items[i].name;
$("#ulList").append("<li>" + fileName + "</li>");
}
}
})
})
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:FileUpload ID="FileUpload1" runat="server" AllowMultiple="true" />
<ul id="ulList"></ul>
</div>
</form>
</body>
It shows as below:

Best Regards
Wei Zhang