在Google开发者控制台中，配置的“重定向URI”必须与使用时C＃代码中所提供的“重定向URI”相同。

以下是一个示例，用于从Google Drive API获取access_token：

public class HomeController : Controller
{
    private static readonly string CLIENT_ID = "your-client-id";
    private static readonly string CLIENT_SECRET = "your-client-secret";
    private static readonly string REDIRECT_URI = "your-redirect-uri";
    
    private static readonly string[] SCOPES = { DriveService.Scope.DriveReadonly };
    
    public ActionResult Index()
    {
        UserCredential credential;
        using (var stream = new FileStream("client_secrets.json", FileMode.Open, FileAccess.Read))
        {
            credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
                GoogleClientSecrets.Load(stream).Secrets,
                SCOPES,
                "user",
                CancellationToken.None,
                new FileDataStore("Drive.Auth.Store")).Result;
        }
        
        var service = new DriveService(new BaseClientService.Initializer()
        {
            HttpClientInitializer = credential,
            ApplicationName = "ASP.NET MVC Google Drive API Sample"
        });
        
        // do something with service
        
        return View();
    }
    
    public ActionResult Auth()
    {
        var uri = new Uri(REDIRECT_URI);
        var flow = new GoogleAuthorizationCodeFlow(new GoogleAuthorizationCodeFlow.Initializer
        {
            ClientSecrets = new ClientSecrets
            {
                ClientId = CLIENT_ID,
                ClientSecret = CLIENT_SECRET
            },
            Scopes = SCOPES
        });
        
        var code = Request.QueryString["code"];
        if (code == null)
        {
            var state = Guid.NewGuid().ToString();
            Session["state"] = state;
            var authUrl = flow.CreateAuthorizationCodeRequest(uri).Build();
            return Redirect(authUrl + "&state=" + state);
        }
        else
        {
            var token = flow.ExchangeCodeForTokenAsync("user", code, uri).Result;
            Session["access_token"] = token.AccessToken;
            Session["refresh_token"] = token.RefreshToken;
            return RedirectToAction("Index");
        }
    }
}

在上述代码示例