c # — Как получить контакты Google?

Я рекомендую использовать API Google People это более новая версия API контактов Google.

OAuth Ссылка на код

private static UserCredential GetUserCredential(string clientSecretJson, string userName, string[] scopes)
{
try
{
if (string.IsNullOrEmpty(userName))
throw new ArgumentNullException("userName");
if (string.IsNullOrEmpty(clientSecretJson))
throw new ArgumentNullException("clientSecretJson");
if (!File.Exists(clientSecretJson))
throw new Exception("clientSecretJson file does not exist.");

// These are the scopes of permissions you need. It is best to request only what you need and not all of them
using (var stream = new FileStream(clientSecretJson, FileMode.Open, FileAccess.Read))
{
string credPath = System.Environment.GetFolderPath(System.Environment.SpecialFolder.Personal);
credPath = Path.Combine(credPath, ".credentials/", System.Reflection.Assembly.GetExecutingAssembly().GetName().Name);

// Requesting Authentication or loading previously stored authentication for userName
var credential = GoogleWebAuthorizationBroker.AuthorizeAsync(GoogleClientSecrets.Load(stream).Secrets,
scopes,
userName,
CancellationToken.None,
new FileDataStore(credPath, true)).Result;

credential.GetAccessTokenForRequestAsync();
return credential;
}
}
catch (Exception ex)
{
throw new Exception("Get user credentials failed.", ex);
}
}

Список Ссылка на код

public static ListConnectionsResponse List(PeopleserviceService service, string resourceName, ConnectionsListOptionalParms optional = null)
{
try
{
// Initial validation.
if (service == null)
throw new ArgumentNullException("service");
if (resourceName == null)
throw new ArgumentNullException(resourceName);

// Building the initial request.
var request = service.Connections.List(resourceName);

// Applying optional parameters to the request.
request = (ConnectionsResource.ListRequest)SampleHelpers.ApplyOptionalParms(request, optional);

// Requesting data.
return request.Execute();
}
catch (Exception ex)
{
throw new Exception("Request Connections.List failed.", ex);
}
}

}

Мой полный пример проекта можно найти Вот