public static class RowChangedEvent 

protected void subRowEvent()
{
  QueuedTask.Run(() =>
  {
    //Listen for row events on a layer
    var featLayer = MapView.Active.GetSelectedLayers().First() as FeatureLayer;
    var layerTable = featLayer.GetTable();

    //subscribe to row events
    var rowCreateToken = RowCreatedEvent.Subscribe(OnRowCreated, layerTable);
    var rowChangeToken = RowChangedEvent.Subscribe(OnRowChanged, layerTable);
    var rowDeleteToken = RowDeletedEvent.Subscribe(OnRowDeleted, layerTable);
  });
}

protected void OnRowCreated(RowChangedEventArgs args)
{
  // RowEvent callbacks are always called on the QueuedTask so there is no need 
  // to wrap your code within a QueuedTask.Run lambda.

  // update a separate table when a row is created
  // You MUST use the ArcGIS.Core.Data API to edit the table. Do NOT
  // use a new edit operation in the RowEvent callbacks
  try
  {
    // update Notes table with information about the new feature
    var geoDatabase = new Geodatabase(new FileGeodatabaseConnectionPath(new Uri(Project.Current.DefaultGeodatabasePath)));
    var table = geoDatabase.OpenDataset<Table>("Notes");
    var tableDefinition = table.GetDefinition();
    using (var rowbuff = table.CreateRowBuffer())
    {
      // add a description
      rowbuff["Description"] = "OID: " + args.Row.GetObjectID().ToString() + " " + DateTime.Now.ToShortTimeString();
      table.CreateRow(rowbuff);
    }
  }
  catch (Exception e)
  {
    MessageBox.Show($@"Error in OnRowCreated for OID: {args.Row.GetObjectID()} : {e.ToString()}");
  }
}


private Guid _currentRowChangedGuid = Guid.Empty;

protected void OnRowChanged(RowChangedEventArgs args)
{
  // RowEvent callbacks are always called on the QueuedTask so there is no need 
  // to wrap your code within a QueuedTask.Run lambda.

  var row = args.Row;

  // check for re-entry  (only if row.Store is called)
  if (_currentRowChangedGuid == args.Guid)
    return;

  var fldIdx = row.FindField("POLICE_DISTRICT");
  if (fldIdx != -1)
  {
    //Validate any change to �police district�
    //   cancel the edit if validation on the field fails
    if (row.HasValueChanged(fldIdx))
    {
      if (FailsValidation(row["POLICE_DISTRICT"].ToString()))
      {
        //Cancel edits with invalid �police district� values
        args.CancelEdit($"Police district {row["POLICE_DISTRICT"]} is invalid");
      }
    }

    // update the description field
    row["Description"] = "Row Changed";

    //  this update with cause another OnRowChanged event to occur
    //  keep track of the row guid to avoid recursion
    _currentRowChangedGuid = args.Guid;
    row.Store();
    _currentRowChangedGuid = Guid.Empty;
  }
}

protected void OnRowDeleted(RowChangedEventArgs args)
{
  var row = args.Row;

  // cancel the delete if the feature is in Police District 5

  var fldIdx = row.FindField("POLICE_DISTRICT");
  if (fldIdx != -1)
  {
    var value = row[fldIdx].ToString();
    if (value == "5")
      args.CancelEdit();
  }
}