Yes, you can add extra code to validate the uploaded files and interrupt the upload process, please refer to the following code:
<%@ Page Language="C#" Title="First sample" %>
<%@ Import Namespace="CuteWebUI" %>
<%@ Register TagPrefix="CuteWebUI" Namespace="CuteWebUI" Assembly="CuteWebUI.AjaxUploader" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN" "
http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">
<script runat="server">
string disabledExtList = "html,htm,mht,exe,dll";
void InsertMsg(string msg)
{
ListBoxEvents.Items.Insert(0, msg);
ListBoxEvents.SelectedIndex = 0;
}
protected void UploadAttachments1_AttachmentAdded(object sender, AttachmentItemEventArgs args)
{
InsertMsg("Added.." + args.Item.FileName);
}
protected void UploadAttachments1_FileValidating(object sender, UploaderEventArgs args)
{
//validate the extensions , this is very important!
//the client side validation is not safe , double check it here:
string ext=Path.GetExtension(args.FileName).TrimStart('.').ToLower();
ext = "," + ext + ",";
string list="," + disabledExtList.ToLower() + ",";
if (list.IndexOf(ext) != -1)
{
throw (new Exception("Invalid file type!"));
}
}
</script>
<html xmlns="
http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
</head>
<body>
<form id="Form1" runat="server">
<script src="../PageUpload/TempSource.js"></script>
<CuteWebUI:UploadAttachments runat="server" ID="UploadAttachments1" OnAttachmentAdded="UploadAttachments1_AttachmentAdded" OnFileValidating="UploadAttachments1_FileValidating">
</CuteWebUI:UploadAttachments>
<br />
<div>
Server Trace:
<br />
<asp:ListBox runat="server" ID="ListBoxEvents" Width="800"></asp:ListBox>
</div>
</form>
<script type="text/javascript">
var disabledExtList = '<%=disabledExtList %>'
</script>
<script type="text/javascript">
//validate the extensions in client side
//this way is not safe , just for performance
//try to disable it to test the server validation
var useclientvalidation = true;
function CuteWebUI_AjaxUploader_OnSelect(files) {
if (useclientvalidation) {
var list = "," + disabledExtList + ",";
for (var i = 0; i < files.length; i++) {
var item = files[i];
var size = item.FileSize;
var fps = item.FileName.split('.');
var ext = fps[fps.length - 1].toLowerCase();
ext = "," + ext + ",";
if (list.indexOf(ext) != -1) {
item.Cancel();
alert("Javascript : Invalid file type : " + ext);
}
}
}
}
</script>
</body>
</html>