I am loading a large datasource into a XamDataGrid and in the FieldLayoutInitialized event handler I'm defining some SummaryDefinition based on Property Attributes.

foreach (var columnDetailsAttribute in attributes.Where(attribute => attribute.TotalsBy || attribute.AverageBy))
{
    var summaryDefinition = new SummaryDefinition();
    summaryDefinition.SourceFieldName = columnDetailsAttribute.PropertyName;
   
    summaryDefinition.Calculator = columnDetailsAttribute.TotalsBy
        ? (SummaryCalculator) Infragistics.Windows.DataPresenter.SummaryCalculator.Sum
        : Infragistics.Windows.DataPresenter.SummaryCalculator.Average;
   
    e.FieldLayout.SummaryDefinitions.Add(summaryDefinition);
}

this works fine.

However I would like to turnoff or not define the SummaryDefinition if the grouping only has one group.