Is it possible to know who view the box file use box API or .net SDK?

Steven, I'm currently looking for the same! Here's something from my learning path:
You could try out the events endpoint, however it requires your app to have admin access (which I cannot get, so not an option for me).
Another way could be to check out webhooks.. I experimented a little bit with this solution; I could only authenticate via 1 hour temporary developer tokens (which means the webhook will also only live for this 1 hour). I would like to use JWT authentication, but haven't had any luck with that. 

Let us know if you try out some of my suggestions and how it goes?

Please also feel free to upvote my suggestions on this matter: https://pulse.box.com/forums/909778-help-shape-the-future-of-box/suggestions/41729881-custom-app-to-pull-access-stats-on-files-folders-w

Cheers!

Hi Chrissy,

Thanks for your suggestion, I tried to create a webhook but I didn't see it was invoked when the file was reviewed. Do you have any suggestions for that? and I only can use temporary developer tokens, not admin token, otherwise, we will encounter privilege issues.

Thanks & Regards

Steven