Providing a C # example is a bit complicated because there are a number of variables, i.e. the signature method used, additional parameters that the service can expect, etc., which will affect the complexity of the example.
I developed the OAuth open-source library for .Net and published an article about starting to use OAuth , which can help you get started - I tried to find the developers / API page for a bright shortcut, but since it's a beta service, I don't have access - so maybe write me an invitation to this service through my blog , and I can practice developing an example of a bright client, at this point this answer can be reviewed using some specific example code that is useful for others.