Hi,
The ChildTable can be made hidden when it has no records to show up, by having a CustomEngine. Derive the GridChildTable in the CustomGroupingEngine and override the GetVisibleCount(), there check whether Records.Count equals 0 for the childtable and return 0. This will make the ChildTable to be hidden when it has no records to show.
In addtion, if the +/- buttons also has to be hidden then, the QueryCellStyleInfo event of the GridGroupiingControl can be handled to do this.
Please refer to the sample,
http://help.syncfusion.com/samples/kb/grid.windows/GGCHideEmptyChildTable/HideEmptyChildTables.zip Regards,
Jisha