无法将类型'Xamarin.Auth.OAuth2Authenticator'隐式转换为'Google.Apis.Http.IConfigurableHttpClientInitializer'

Question

我正在尝试使用带有流动代码和身份验证的Google云端硬盘服务

var auth = new OAuth2Authenticator (
clientId: xxxxxxxx
scope: "https://www.googleapis.com/auth/drive",
authorizeUrl: new Uri ("https://accounts.google.com/o/oauth2/auth"),
redirectUrl: new Uri ("myredirect:oob"));

并尝试按

初始化Google云端硬盘服务

var service = new DriveService(new BaseClientService.Initializer()
{
HttpClientInitializer = auth,
ApplicationName = "Google Drive API Sample",
});

但上面的代码显示错误 错误CS0266：无法隐式转换类型＆＃39; Xamarin.Auth.OAuth2Authenticator＆＃39;到Google.Apis.Http.IConfigurableHttpClientInitializer＆＃39;。存在显式转换（您是否缺少演员？）（CS0266）