See the similar answer I've given here:
DataBound and RowDataBound[
^]
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.
Refer :
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 ()[
^]
Hope now it's clear to you. :)
--Amit