I have an application file that is hosted on a webserver. The client app needs to regularly check for changes to this file and download the new version. I will use the WebClient class to download the file, but I don't want to download it if it hasn't changed. It's like caching at the client application level. Is there a simple way to find out the modified date of the file programmatically through the webserver? Then I can do a quick check to see if the file has changed, and only download the updates when required.

The fallback is to host a 2nd file which contains just the modified date or version number. The client could use WebClient to download this small file, check if that has changed, and then download the larger file, but that is extra overhead. If there is a simple way to check the date of the hosted file, then that would be preferable.