public Table GetOriginTable()

{
  // GetDefinitionFromLayer - This code works even if the layer has a join to another table
  //Must be called within QueuedTask.Run()
  TableDefinition GetDefinitionFromLayer(FeatureLayer featureLayer)
  {
    // Get feature class from the layer
    FeatureClass featureClass = featureLayer.GetFeatureClass();

    // Determine if feature class is a join
    if (featureClass.IsJoinedTable())
    {
      // Get join from feature class
      Join join = featureClass.GetJoin();

      // Get origin table from join
      Table originTable = join.GetOriginTable();

      // Return feature class definition from the join's origin table
      return originTable.GetDefinition();
    }
    return featureClass.GetDefinition();
  }
}