Use the SelectedIndex property to determine the index of the currently selected row in a GridView control. You can also use this property to programmatically select a row in the control. To clear the selection of a row, set this property to -1. The appearance of the currently selected row can be customized by using the SelectedRowStyle property. To access the currently selected row, use the SelectedRow property.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2