Using DotNetOpenAuth to get both Contacts & Calendars from a Google account together

I am writing a web application using ASP.NET MVC3 (C#), and I need to get the calendars and contacts from my logged-in user's Google account(s).开发者_如何学Go

Because I don't want to store the user's credentials, I am using OAuth (but not doing OpenID - I don't want my users to log in using their Google account).

I have the following code to get the access token and later use it to get the data:

var google = new WebConsumer(GoogleConsumer.ServiceDescription, this.TokenManager);

// Is Google calling back with authorization?
var accessTokenResponse = google.ProcessUserAuthorization();
if (accessTokenResponse != null) {
    this.AccessToken = accessTokenResponse.AccessToken;
    //SAVE ACCESS TOKEN TO DATABASE
} else if (this.AccessToken == null) {
    // If we don't yet have access, immediately request it.
    GoogleConsumer.RequestAuthorization(google, GoogleConsumer.Applications.Contacts);
}

Unfortunately, as you can see, I'm only requesting authorization for the Contacts, and the RequestAuthorization method doesn't allow me to set more than one application.

How can I do it without the need for several different tokens for the different scopes? (One for Calendar, one for Contacts, etc.)

---

The GoogleConsumer class is provided as source code to you in the DotNetOpenAuth.ApplicationBlock project. Please feel free to modify it to do just what you need.

---

Scopes can be placed in a string and separated by spaces

EDIT: Added from poster's comments

I use the following code when creating the scope string:

foreach (String s in Scopes) {
    sb.Append(String.Format("{0}", s));
}
scope = sb.ToString().Trim();

Where Scopes is an array of Strings (String[]) containing the scopes I want to use. When you request authorization from Google, then, you will see the list of services being requested displayed on the login screen.