OnClientFileUploading
The OnClientFileUploading client-side event occurs when a file has starteduploading.
The event handler receives two parameters:
The instance of the RadAsyncUpload control firing the event.
An eventArgs parameter containing the following methods:
get_row returns the row containing the file input field for the file that was just selected (<li> element)
get_fileName returns the name of the file selected
set_cancel cancel the upload process
<telerik:RadAsyncUpload RenderMode="Lightweight" runat="server" ID="RadAsyncUpload1" OnClientFileUploading="OnClientFileUploading"></telerik:RadAsyncUpload>
function OnClientFileUploading(sender, args) {
alert(args.get_fileName().length);
if (args.get_fileName().length > 20) {
args.set_cancel(true);
}
else {
args.set_cancel(false);
}
}