Occurs when an Update button within a System.Web.UI.WebControls.DetailsView control is clicked, but before the update operation.
The DetailsView.ItemUpdating event is raised when an Update button within a System.Web.UI.WebControls.DetailsView control is clicked, but before the update operation. This allows you to provide an event handler that performs a custom routine, such as canceling the update operation, whenever this event occurs.
A System.Web.UI.WebControls.DetailsViewUpdateEventArgs object is passed to the event handler, which allows you to determine the index of the record being updated and to indicate that the update operation should be canceled. To cancel the update operation, set the System.ComponentModel.CancelEventArgs.Cancel property to true. You can also manipulate the DetailsViewUpdateEventArgs.Keys, DetailsViewUpdateEventArgs.OldValues, and DetailsViewUpdateEventArgs.NewValues collections, if necessary, before the values are passed to the data source. A common way to use these collections is to HTML-encode the values supplied by the user before they are stored in the data source. This helps to prevent script injection attacks.
For more information about handling events, see Consuming Events.