How do I use oAuth with Google C# .NET APIs? - oauth-2.0

Question

I am trying to use the .NET APIs from Google
https://code.google.com/p/google-api-dotnet-client/
https://www.nuget.org/packages/Google.Apis.Authentication/
As most of these APIs from Google require an oAuth token for you to fetch any data from them, I am struggling to get over this first hurdle.
My plan is to create a very simple .NET Web API that lists out my Google Analytic's accounts via the API which I can then in turn use with AngularJS to bind to a nice little view with the JSON returned from my WebAPI call.
The problem I mentioned is that there seems to be lots of different examples floating about and I can't seem to get any to to work. Either its out of date or the sample project doesn't compile etc...
From what I can understand I need to pass an Authenticator object to the BaseClient object which is in turn used for any Service API.
Below is a rough example I am trying to get to work, but currently fails and gets an error back from Google's API because I am not logged in/passing an oAuth token. Can anyone give me any pointers or advice please.
Thanks, Warren
[HttpGet]
public IEnumerable<Account> GetAccounts()
{
var baseClient = new BaseClientService.Initializer();
baseClient.ApplicationName = "Google Stats Example";
baseClient.Authenticator = null; //Unsure how to get the oAuth token
AnalyticsService stats = new AnalyticsService(baseClient);
var accounts = stats.Management.Accounts.List();
var allAccounts = accounts.Execute();
return allAccounts.Items;
}

Answer 1

To create an authenticator you need a nuget package named "Google APIs OAuth2 Client Library" but i downloaded a nugget package named "Google.Apis.Oauth2.v2 Client Library". Similar names but not the same.
I was not able to find the correct one on nugget page. If you perform a search on that package it wont show up. I had to use Visual Studio Nugget searcher and activate "show prerealese packages" to install it.