How to cancal file uplading if the file size is zero?

[john]

How to cancal file uplading and alert a message if the uploaded file size is zero?

[Plamen]

Hello,

 
This can not be done on the client-side but you can use the OnFileUploaded event and if the e.File.ContentLength is zero to set the "IsValid" property to false. 

Hope this will be helpful.

Greetings,
Plamen
the Telerik team

[john]

How can I check it in client side instead of server side?

[Plamen]

Hello,

 
Unfortunately this can not be checked on the client side.

All the best,
Plamen
the Telerik team