Occurs when one of the pager buttons is clicked, but before the System.Web.UI.WebControls.GridView control handles the paging operation.
The GridView.PageIndexChanging event is raised when one of the pager buttons is clicked, but before the System.Web.UI.WebControls.GridView control handles the paging operation. This enables you to provide an event-handling method that performs a custom routine, such as canceling the paging operation, whenever this event occurs.
This event is not raised when you programmatically set the GridView.PageIndex property.
A System.Web.UI.WebControls.GridViewPageEventArgs object is passed to the event-handling method, which enables you to determine the index of the page selected by the user and to indicate that the paging operation should be canceled. To cancel the paging operation, set the System.ComponentModel.CancelEventArgs.Cancel property of the System.Web.UI.WebControls.GridViewPageEventArgs object to true.
For more information about handling events, see Consuming Events.