You are correct - the ItemCommand server event will give you only the item's path. I think that there are two possible workarounds for your scenario - you can save the path in the ItemCommand event and then wait for the file to be stored and later in the page life cycle (e.g. in the PreRender event) use the file path to access the stored file and check its size. The other workaround requires a bit more code but it is cleaner because you intercept the save operation and check the size there. You need to customize the default content provider for the file explorer (http://www.telerik.com/help/aspnet-ajax/radfileexplorer-custom-filebrowsercontentprovider.html
) and override the StoreFile() method. In this method you will have full access to the uploaded file and can decide whether to proceed with the save or discard it.
the Telerik team