Before the GridView control can be rendered, each row in the control must be bound to a record in the data source. The RowDataBound
event is raised when a data row (represented by a GridViewRow object) is bound to data in the GridView control. This enables you to provide an event-handling method that performs a custom routine, such as modifying the values of the data bound to the row, whenever this event occurs.
MDSN : GridView.RowDataBound Event
MDSN : GridView.OnRowDataBound Method
We use gridview DataBound
event when we want to do certain things after the server controls bind to the datasource. For example after the binding we may want to display some text at the bottom of the grid or we might want to calculate the total value of a column.
MSDN : GridView.DataBind Method
MSDN : GridView.DataBind Method ()
All the best.