true, to show the summary panel within the grid; otherwise, false.
A total summary represents the value of an aggregate function calculated over all data rows displayed within the grid. Total summaries are displayed within the Summary Panel or Fixed Summary Panel, provided that the DataControlBase.ShowTotalSummary and DataControlBase.ShowFixedTotalSummary options are enabled, respectively. Summaries displayed within the Fixed Summary Panel are not horizontally scrolled. They are always visible onscreen, regardless of the corresponding column's position and visibility.