问题
The use-case is the following: a mobile app is authenticating a user with Google and at some point, we need to publish a user's video to his YouTube account; for practical reasons, the actual publication should be done by the back-end (large files that are already stored there).
As the user is already authenticated by the app, the app just sends the user's access token to the back-end. Now my struggle is to find how to use this access token with the .NET client... So far I've tried to create instances of UserCredential from that access token but that doesn't seem to work. Also we don't need all the token refresh logic provided by UserCredential as we know that the access token is valid at this point.
Any help would be greatly appreciated, thanks!
来源：https://stackoverflow.com/questions/41039044/using-the-google-api-net-client-with-an-existing-access-token