public abstract Connector GetConnector()

{
  await QueuedTask.Run(() =>
  {
    Layer selectedLayer = MapView.Active.GetSelectedLayers()[0];

    if (selectedLayer is FeatureLayer)
    {
      FeatureLayer featureLayer = selectedLayer as FeatureLayer;

      using (Table table = featureLayer.GetTable())
      using (Datastore datastore = table.GetDatastore())
      {
        ServiceConnectionProperties serviceConnectionProperties = datastore.GetConnector() as ServiceConnectionProperties;

        if (serviceConnectionProperties == null)
          return;

        Uri url = serviceConnectionProperties.URL;      // Will be the URL to the Feature Service.
        string user = serviceConnectionProperties.User;     // The username property will only be
                                                            // populated for feature service hosted
                                                            // on non-federated ArcGIS Server.
        string password = serviceConnectionProperties.Password; // Will always be empty.
      }
    }
  });
}