Hi Bob,
Sorry for delay in responding.
It is possible to find out the number of rows painted in the TabControlAdv. Please do find the sample in the following link.
http://websamples.syncfusion.com/samples/Tools.Windows/F70076_New/main.htmIn the sample above I have derived TabControlAdv and created a custom TabControlAdv and GetNumOfRows method to find out number of rows painted in the TabControlAdv.
Thanks for your interest in Syncfusion Products.
Regards,
Fathima