This GridView example demonstrates handling button click events for a row in a
GridView.
Column 1: BoundField column that is bound to the database field Description.
Column 2: BoundField column that is bound to the database field Price.
Column 3: ButtonField column with Add to Card button. CommandName Property is
set to "AddToCart", which is used to determine the button that was clicked and
execute the appropriate code in the Codebehind.
Column 4: ButtonField column Product Reviews button. CommandName Property is set to "ProductReviews"
which is used to determine the button that was clicked and execute the
appropriate code in the Codebehind.
This example also demonstrates the technique of using DataKeys to store and retrieve hidden field values.
The GridView control's property DataKeyNames="ProductNumber" is used to store the
ProductNumber field value for each record in the DataKeys collection.