I would like to implement the following functionality:
A C# client connects to an HTTP server and downloads an image to disk.
The next time the client starts checks if the image on the server is newer than the image on disk, and in this case, the client overrides the image on disk.
For me it's easy to download the image, but I'm not sure how to check if the image on the server is newer. How could I implement it? I guess that I could check the timestamp, or the image size (or both) but I don't know how to do it.