asp.net file downloading - track downloaded size

Question

I am trying to design a system for something like this with ASP.net/C#.

The users pay for downloading some content (files- mp3s/PDFs,doc etc).I should be able to tra

Answer 1

The size you want is the size (not the size on disk). Size on disk includes extra space that is taken up by fitting into the 4K block size of the partition. The size is the exact number of bits in the file.

I don't believe there is a good way to tell that a download has been completed. Response.TransmitFile is probably the best method for sending the file securely. But I don't believe it has anything that will tell you if the user actually recieved the file.

I don't know about the business this is supporting, but I can't think of a legitimate business where users would tolerate a single download per purchase model, and with the abiguity of the standard HTTP request/response model does not lend itself to making an accurate client side reciever. Not to mention this model could be eaisyly hacked by sending a failed response on reciept of the last packet.

I think using somthing like download windows (2hrs after purchase) and then lock it to an IP after the first request would accomplish the same result and result in alot less user issues and support calls. Also unless the file has some sort of stringent DRM, allowing the user persisten access based on their loggin is most likely the appropriate business model, because once they get the file they can copy it as many times as they like.

Look at DVD or Blu-Ray, no amount of copy protection or access controls will save your files from pirates, so make things easy for legitimate users.