private void Yandexauthwindow_Loaded(object sender, RoutedEventArgs e) { var client = new YandexClient ( "ef69cea3cf4946d0b00dec064f1b26ee", "9446b005f22f4a5592b5a78d250551d2" ); if (!OAuthManager.IsRegisteredClient("Yandex")) { OAuthManager.RegisterClient ( client ); } yandexweb.Navigate(source: OAuthWeb.GetAuthorizationUrl("Yandex")); }