public Task LoadAsync( 
   MapMember member,
   long oid
)

// get the first feature layer in the map
var firstFeatureLayer = ArcGIS.Desktop.Mapping.MapView.Active.Map.GetLayersAsFlattenedList().
    OfType<ArcGIS.Desktop.Mapping.FeatureLayer>().FirstOrDefault();

// create an instance of the inspector class
var inspector = new ArcGIS.Desktop.Editing.Attributes.Inspector();
// load the feature with ObjectID 'oid' into the inspector
await inspector.LoadAsync(firstFeatureLayer, oid);

// get the currently selected features in the map
var selectedFeatures = ArcGIS.Desktop.Mapping.MapView.Active.Map.GetSelection();
// get the first layer and its corresponding selected feature OIDs
var firstSelectionSet = selectedFeatures.ToDictionary().First();

// create an instance of the inspector class
var inspector = new ArcGIS.Desktop.Editing.Attributes.Inspector();
// load the selected features into the inspector using a list of object IDs
await inspector.LoadAsync(firstSelectionSet.Key, firstSelectionSet.Value);